diff --git a/src/dos/dos_files.cpp b/src/dos/dos_files.cpp
index c386751b..0b69a627 100644
--- a/src/dos/dos_files.cpp
+++ b/src/dos/dos_files.cpp
@@ -16,7 +16,7 @@
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/* $Id: dos_files.cpp,v 1.64 2005-08-10 16:46:15 qbix79 Exp $ */
+/* $Id: dos_files.cpp,v 1.65 2005-08-19 07:13:34 qbix79 Exp $ */
 
 #include <string.h>
 #include <stdlib.h>
@@ -198,8 +198,20 @@ bool DOS_ChangeDir(char * dir) {
 
 bool DOS_MakeDir(char * dir) {
 	Bit8u drive;char fulldir[DOS_PATHLENGTH];
+	size_t len = strlen(dir);
+	if(!len || dir[len-1] == '\\') {
+		DOS_SetError(DOSERR_PATH_NOT_FOUND);
+		return false;
+	}
 	if (!DOS_MakeName(dir,fulldir,&drive)) return false;
-	return Drives[drive]->MakeDir(fulldir);
+	if(Drives[drive]->MakeDir(fulldir)) return true;
+
+	/* Determine reason for failing */
+	if(Drives[drive]->TestDir(fulldir)) 
+		DOS_SetError(DOSERR_ACCESS_DENIED);
+	else
+		DOS_SetError(DOSERR_PATH_NOT_FOUND);
+	return false;
 }
 
 bool DOS_RemoveDir(char * dir) {
@@ -245,6 +257,12 @@ bool DOS_FindFirst(char * search,Bit16u attr,bool fcb_findfirst) {
 	DOS_DTA dta(dos.dta());
 	Bit8u drive;char fullsearch[DOS_PATHLENGTH];
 	char dir[DOS_PATHLENGTH];char pattern[DOS_PATHLENGTH];
+	size_t len = strlen(search);
+	if(len && search[len - 1] == '\\') { 
+		//Dark Forces installer
+		DOS_SetError(DOSERR_NO_MORE_FILES);
+		return false;
+	}
 	if (!DOS_MakeName(search,fullsearch,&drive)) return false;
 	/* Split the search in dir and pattern */
 	char * find_last;
@@ -510,7 +528,7 @@ bool DOS_SetFileAttr(char * name,Bit16u attr)
 	Bit16u attrTemp;
 	char fullname[DOS_PATHLENGTH];Bit8u drive;
 	if (!DOS_MakeName(name,fullname,&drive)) return false;	
-	if (strcmp(Drives[drive]->GetInfo(),"CDRom.")==0) {
+	if (strcmp(Drives[drive]->GetInfo(),"CDRom.")==0 || strcmp(Drives[drive]->GetInfo(),"isoDrive")==0) {
 		DOS_SetError(DOSERR_ACCESS_DENIED);
 		return false;
 	}
diff --git a/src/dos/drive_local.cpp b/src/dos/drive_local.cpp
index 8e6d144b..a38e66af 100644
--- a/src/dos/drive_local.cpp
+++ b/src/dos/drive_local.cpp
@@ -16,7 +16,7 @@
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/* $Id: drive_local.cpp,v 1.60 2005-08-11 18:57:48 qbix79 Exp $ */
+/* $Id: drive_local.cpp,v 1.61 2005-08-19 07:13:34 qbix79 Exp $ */
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -205,7 +205,6 @@ bool localDrive::FindNext(DOS_DTA & dta) {
 	Bit8u find_attr;
 
 	dta.GetSearchParams(srch_attr,srch_pattern);
-	
 	Bitu id = dta.GetDirID();
 
 again:
@@ -279,8 +278,8 @@ bool localDrive::MakeDir(char * dir) {
 	int temp=mkdir(dirCache.GetExpandName(newdir),0700);
 #endif
 	if (temp==0) dirCache.CacheOut(newdir,true);
-	// if dir already exists, return success too.
-	return (temp==0) || ((temp!=0) && (errno==EEXIST));
+
+	return (temp==0);// || ((temp!=0) && (errno==EEXIST));
 }
 
 bool localDrive::RemoveDir(char * dir) {
@@ -300,8 +299,8 @@ bool localDrive::TestDir(char * dir) {
 	CROSS_FILENAME(newdir);
 	dirCache.ExpandName(newdir);
 	// Skip directory test, if "\"
-	Bit16u len = strlen(newdir);
-	if ((len>0) && (newdir[len-1]!='\\')) {
+	size_t len = strlen(newdir);
+	if (len && (newdir[len-1]!='\\')) {
 		// It has to be a directory !
 		struct stat test;
 		if (stat(newdir,&test)==-1)			return false;