diff --git a/include/wx/strconv.h b/include/wx/strconv.h
index cf508681b7..92d5729370 100644
--- a/include/wx/strconv.h
+++ b/include/wx/strconv.h
@@ -146,7 +146,7 @@ WXDLLEXPORT_DATA(extern wxMBConv *) wxConvCurrent;
 // ----------------------------------------------------------------------------
 
 // filenames are multibyte on Unix and probably widechar on Windows?
-#if defined(__UNIX__) || defined(__WIN32__)
+#if defined(__UNIX__) || defined(__BORLANDC__)
     #define wxMBFILES 1
 #else
     #define wxMBFILES 0
diff --git a/src/common/docview.cpp b/src/common/docview.cpp
index e96aaa3e04..3e894aa0d1 100644
--- a/src/common/docview.cpp
+++ b/src/common/docview.cpp
@@ -2199,7 +2199,7 @@ bool wxTransferFileToStream(const wxString& filename, wxOutputStream& stream)
     FILE *fd1;
     int ch;
 
-    if ((fd1 = fopen (filename.fn_str(), "rb")) == NULL)
+    if ((fd1 = wxFopen (filename.fn_str(), wxT("rb"))) == NULL)
         return FALSE;
 
     while ((ch = getc (fd1)) != EOF)
@@ -2214,7 +2214,7 @@ bool wxTransferStreamToFile(wxInputStream& stream, const wxString& filename)
     FILE *fd1;
     char ch;
 
-    if ((fd1 = fopen (filename.fn_str(), "wb")) == NULL)
+    if ((fd1 = wxFopen (filename.fn_str(), wxT("wb"))) == NULL)
     {
         return FALSE;
     }
diff --git a/src/common/filefn.cpp b/src/common/filefn.cpp
index 4a4f4ddfcc..308c2f5246 100644
--- a/src/common/filefn.cpp
+++ b/src/common/filefn.cpp
@@ -1163,7 +1163,7 @@ bool wxPathExists(const wxChar *pszPathName)
   /* Windows API returns -1 from stat for "c:\dir\" if "c:\dir" exists
    * OTOH, we should change "d:" to "d:\" and leave "\" as is. */
   wxString strPath(pszPathName);
-  if ( wxEndsWithPathSeparator(pszPathName) && pszPathName[1] != wxT('\0') )
+  if ( wxEndsWithPathSeparator(pszPathName) && pszPathName[1] != wxT('\0') && pszPathName[1] != wxT(':') )
     strPath.Last() = wxT('\0');
 
   wxStructStat st;
diff --git a/src/common/fs_zip.cpp b/src/common/fs_zip.cpp
index 8a41c21b6b..706cd05352 100644
--- a/src/common/fs_zip.cpp
+++ b/src/common/fs_zip.cpp
@@ -118,7 +118,7 @@ wxString wxZipFSHandler::FindFirst(const wxString& spec, int flags)
     }
 
     m_ZipFile = left;
-    m_Archive = (void*) unzOpen(m_ZipFile.fn_str());
+    m_Archive = (void*) unzOpen(m_ZipFile.mb_str());
     m_Pattern = right.AfterLast(wxT('/'));
     m_BaseDir = right.BeforeLast(wxT('/'));
 
diff --git a/src/common/memory.cpp b/src/common/memory.cpp
index 946cad0122..902a88a2f2 100644
--- a/src/common/memory.cpp
+++ b/src/common/memory.cpp
@@ -519,7 +519,7 @@ void wxDebugContext::SetStream(ostream *str, streambuf *buf)
 
 bool wxDebugContext::SetFile(const wxString& file)
 {
-  ofstream *str = new ofstream(file.fn_str());
+  ofstream *str = new ofstream(file.mb_str());
 
   if (str->bad())
   {
@@ -1026,7 +1026,7 @@ void operator delete(void* pData, wxChar* /* fileName */, int /* lineNum */)
   wxDebugFree(pData, FALSE);
 }
 // New operator 21/11/1998
-void operator delete[](void* pData, char* /* fileName */, int /* lineNum */)
+void operator delete[](void* pData, wxChar* /* fileName */, int /* lineNum */)
 {
   wxDebugFree(pData, TRUE);
 }
diff --git a/src/common/zipstrm.cpp b/src/common/zipstrm.cpp
index 54cb0c8638..c8a864bd72 100644
--- a/src/common/zipstrm.cpp
+++ b/src/common/zipstrm.cpp
@@ -39,13 +39,13 @@ wxZipInputStream::wxZipInputStream(const wxString& archive, const wxString& file
 
     m_Pos = 0;
     m_Size = 0;
-    m_Archive = (void*) unzOpen(archive.fn_str());
+    m_Archive = (void*) unzOpen(archive.mb_str());
     if (m_Archive == NULL)
     {
         m_lasterror = wxStream_READ_ERR;
         return;
     }
-    if (unzLocateFile((unzFile)m_Archive, file.fn_str(), 0) != UNZ_OK)
+    if (unzLocateFile((unzFile)m_Archive, file.mb_str(), 0) != UNZ_OK)
     {
         m_lasterror = wxStream_READ_ERR;
         return;
diff --git a/src/generic/helphtml.cpp b/src/generic/helphtml.cpp
index 8970ba2416..2005af7c14 100644
--- a/src/generic/helphtml.cpp
+++ b/src/generic/helphtml.cpp
@@ -166,7 +166,7 @@ wxHTMLHelpControllerBase::LoadFile(const wxString& ifile)
    m_MapList = new wxList;
    m_NumOfEntries = 0;
 
-   FILE *input = fopen(mapFile.fn_str(),"rt");
+   FILE *input = wxFopen(mapFile.fn_str(),wxT("rt"));
    if(! input)
       return FALSE;
    do
diff --git a/src/msw/metafile.cpp b/src/msw/metafile.cpp
index e7c7270724..ce2568c2c2 100644
--- a/src/msw/metafile.cpp
+++ b/src/msw/metafile.cpp
@@ -379,12 +379,12 @@ bool wxMakeMetafilePlaceable(const wxString& filename, int x1, int y1, int x2, i
             p < (WORD *)&pMFHead ->checksum; ++p)
         pMFHead ->checksum ^= *p;
 
-    FILE *fd = fopen(filename.fn_str(), "rb");
+    FILE *fd = wxFopen(filename.fn_str(), "rb");
     if (!fd) return FALSE;
 
     wxChar tempFileBuf[256];
     wxGetTempFileName(wxT("mf"), tempFileBuf);
-    FILE *fHandle = fopen(wxConvFile.cWX2MB(tempFileBuf), "wb");
+    FILE *fHandle = wxFopen(wxConvFile.cWX2MB(tempFileBuf), "wb");
     if (!fHandle)
         return FALSE;
     fwrite((void *)&header, sizeof(unsigned char), sizeof(mfPLACEABLEHEADER), fHandle);