diff --git a/core/hw/mem/vmem32.cpp b/core/hw/mem/vmem32.cpp
index fab4a29ca..d27fa569e 100644
--- a/core/hw/mem/vmem32.cpp
+++ b/core/hw/mem/vmem32.cpp
@@ -249,6 +249,7 @@ static u32 vmem32_map_mmu(u32 address, bool write)
 		if (offset == -1)
 			return VMEM32_ERROR_NOT_MAPPED;
 
+		bool allow_write = (entry->Data.PR & 1) != 0;
 		if (offset >= MAP_VRAM_START_OFFSET && offset < MAP_VRAM_START_OFFSET + VRAM_SIZE)
 		{
 			// Check vram protected regions
@@ -262,7 +263,7 @@ static u32 vmem32_map_mmu(u32 address, bool write)
 
 				return MMU_ERROR_NONE;
 			}
-			verify(vmem32_map_buffer(vpn, page_size, offset, page_size, (entry->Data.PR & 1) != 0) != NULL);
+			verify(vmem32_map_buffer(vpn, page_size, offset, page_size, allow_write) != NULL);
 			u32 end = start + page_size;
 			const vector<vram_lock>& blocks = vram_blocks[start / VRAM_PROT_SEGMENT];
 
@@ -281,12 +282,14 @@ static u32 vmem32_map_mmu(u32 address, bool write)
 			vramlist_lock.Unlock();
 
 		}
-		else if (offset >= MAP_VRAM_START_OFFSET && offset < MAP_VRAM_START_OFFSET + VRAM_SIZE)
+		else if (offset >= MAP_RAM_START_OFFSET && offset < MAP_RAM_START_OFFSET + RAM_SIZE)
 		{
 			// Check system RAM protected pages
-			if (bm_IsRamPageProtected(ppn))
+			u32 start = offset - MAP_RAM_START_OFFSET;
+
+			if (bm_IsRamPageProtected(start) && allow_write)
 			{
-				if (sram_mapped_pages[ppn >> 15] & (1 << ((ppn >> 12) & 7)))
+				if (sram_mapped_pages[start >> 15] & (1 << ((start >> 12) & 7)))
 				{
 					// Already mapped => write access
 					vmem32_unprotect_buffer(address & ~PAGE_MASK, PAGE_SIZE);
@@ -294,16 +297,16 @@ static u32 vmem32_map_mmu(u32 address, bool write)
 				}
 				else
 				{
-					sram_mapped_pages[ppn >> 15] |= (1 << ((ppn >> 12) & 7));
+					sram_mapped_pages[start >> 15] |= (1 << ((start >> 12) & 7));
 					verify(vmem32_map_buffer(vpn, page_size, offset, page_size, false) != NULL);
 				}
 			}
 			else
-				verify(vmem32_map_buffer(vpn, page_size, offset, page_size, (entry->Data.PR & 1) != 0) != NULL);
+				verify(vmem32_map_buffer(vpn, page_size, offset, page_size, allow_write) != NULL);
 		}
 		else
 			// Not vram or system ram
-			verify(vmem32_map_buffer(vpn, page_size, offset, page_size, (entry->Data.PR & 1) != 0) != NULL);
+			verify(vmem32_map_buffer(vpn, page_size, offset, page_size, allow_write) != NULL);
 
 		return MMU_ERROR_NONE;
 	}
diff --git a/core/hw/pvr/Renderer_if.cpp b/core/hw/pvr/Renderer_if.cpp
index eada63387..bfa7c94df 100644
--- a/core/hw/pvr/Renderer_if.cpp
+++ b/core/hw/pvr/Renderer_if.cpp
@@ -255,7 +255,7 @@ bool rend_frame(TA_context* ctx, bool draw_osd) {
 	bool proc = renderer->Process(ctx);
 	if ((ctx->rend.isRTT || ctx->rend.isRenderFramebuffer) && swap_pending)
 	{
-		// If there a frame swap pending, we want to do it now.
+		// If there is a frame swap pending, we want to do it now.
 		// The current frame "swapping" detection mechanism (using FB_R_SOF1) doesn't work
 		// if a RTT frame is rendered in between.
 		renderer->Present();
diff --git a/core/hw/sh4/dyna/blockmanager.cpp b/core/hw/sh4/dyna/blockmanager.cpp
index dc32785f1..a95c4d407 100644
--- a/core/hw/sh4/dyna/blockmanager.cpp
+++ b/core/hw/sh4/dyna/blockmanager.cpp
@@ -653,10 +653,13 @@ void bm_Sort()
 
 RuntimeBlockInfo::~RuntimeBlockInfo()
 {
-	if (read_only)
-		protected_blocks--;
-	else
-		unprotected_blocks--;
+	if (sh4_code_size != 0)
+	{
+		if (read_only)
+			protected_blocks--;
+		else
+			unprotected_blocks--;
+	}
 }
 
 void RuntimeBlockInfo::AddRef(RuntimeBlockInfoPtr other)
@@ -699,8 +702,7 @@ void RuntimeBlockInfo::Discard()
 void RuntimeBlockInfo::SetProtectedFlags()
 {
 	// Don't write protect rom
-	// TODO Enable this for wince. hangs 4x4 EVO
-	if (mmu_enabled() || (!IsOnRam(addr) /*|| (vaddr & 0x1FFF0000) == 0x0C000000 */))
+	if (!IsOnRam(addr))
 	{
 		this->read_only = false;
 		unprotected_blocks++;
@@ -746,7 +748,7 @@ void bm_RamWriteAccess(u32 addr)
 	verify(block_list.empty());
 }
 
-bool bm_RamWriteAccess(void *p, unat pc)
+bool bm_RamWriteAccess(void *p)
 {
 	if (_nvmem_4gb_space())
 	{
diff --git a/core/hw/sh4/dyna/blockmanager.h b/core/hw/sh4/dyna/blockmanager.h
index 0d135a117..293bd7124 100644
--- a/core/hw/sh4/dyna/blockmanager.h
+++ b/core/hw/sh4/dyna/blockmanager.h
@@ -106,7 +106,7 @@ void bm_Init();
 void bm_Term();
 
 void bm_vmem_pagefill(void** ptr,u32 PAGE_SZ);
-bool bm_RamWriteAccess(void *p, unat pc);
+bool bm_RamWriteAccess(void *p);
 void bm_RamWriteAccess(u32 addr);
 static inline bool bm_IsRamPageProtected(u32 addr)
 {
diff --git a/core/hw/sh4/dyna/driver.cpp b/core/hw/sh4/dyna/driver.cpp
index a9633c659..936d077cb 100644
--- a/core/hw/sh4/dyna/driver.cpp
+++ b/core/hw/sh4/dyna/driver.cpp
@@ -237,6 +237,7 @@ bool RuntimeBlockInfo::Setup(u32 rpc,fpscr_t rfpu_cfg)
 {
 	staging_runs=addr=lookups=runs=host_code_size=0;
 	guest_cycles=guest_opcodes=host_opcodes=0;
+	sh4_code_size = 0;
 	pBranchBlock=pNextBlock=0;
 	code=0;
 	has_jcond=false;
diff --git a/core/linux/common.cpp b/core/linux/common.cpp
index 3a3b6df9a..879e7c887 100644
--- a/core/linux/common.cpp
+++ b/core/linux/common.cpp
@@ -71,7 +71,7 @@ void fault_handler (int sn, siginfo_t * si, void *segfault_ctx)
 	if (vmem32_handle_signal(si->si_addr, write, exception_pc))
 		return;
 #endif
-	if (bm_RamWriteAccess(si->si_addr, ctx.pc))
+	if (bm_RamWriteAccess(si->si_addr))
 		return;
 	if (VramLockedWrite((u8*)si->si_addr) || BM_LockedWrite((u8*)si->si_addr))
 		return;
diff --git a/core/stdclass.h b/core/stdclass.h
index 39640f5d8..7b6cd17d0 100644
--- a/core/stdclass.h
+++ b/core/stdclass.h
@@ -287,7 +287,7 @@ bool mem_region_release(void *start, size_t len);
 void *mem_region_map_file(void *file_handle, void *dest, size_t len, size_t offset, bool readwrite);
 bool mem_region_unmap_file(void *start, size_t len);
 
-// Locked memory class, used for texture invalidation purposes.
+// Locked memory class, was used for texture invalidation purposes.
 class VLockedMemory {
 public:
 	u8* data;
@@ -300,23 +300,7 @@ public:
 	void *getPtr() const { return data; }
 	unsigned getSize() const { return size; }
 
-	#ifdef TARGET_NO_EXCEPTIONS
-	void LockRegion(unsigned offset, unsigned size_bytes) {}
-	void UnLockRegion(unsigned offset, unsigned size_bytes) {}
-	#else
-	void LockRegion(unsigned offset, unsigned size_bytes)
-	{
-		mem_region_lock(&data[offset], size_bytes);
-	}
-
-	void UnLockRegion(unsigned offset, unsigned size_bytes)
-	{
-		mem_region_unlock(&data[offset], size_bytes);
-	}
-	#endif
-
 	void Zero() {
-		UnLockRegion(0, size);
 		memset(data, 0, size);
 	}
 
diff --git a/core/windows/winmain.cpp b/core/windows/winmain.cpp
index 7a9a2d39b..4caac6764 100644
--- a/core/windows/winmain.cpp
+++ b/core/windows/winmain.cpp
@@ -150,7 +150,7 @@ LONG ExeptionHandler(EXCEPTION_POINTERS *ExceptionInfo)
 	if (vmem32_handle_signal(address, write, 0))
 		return EXCEPTION_CONTINUE_EXECUTION;
 #endif
-	if (bm_RamWriteAccess(address, 0))
+	if (bm_RamWriteAccess(address))
 	{
 		return EXCEPTION_CONTINUE_EXECUTION;
 	}