diff -r e880629062dd -r e4a7b1cbe40c userlibandfileserver/fileserver/sfile/sf_utl.cpp
--- a/userlibandfileserver/fileserver/sfile/sf_utl.cpp	Wed May 05 05:11:16 2010 +0100
+++ b/userlibandfileserver/fileserver/sfile/sf_utl.cpp	Mon May 10 11:40:53 2010 +0100
@@ -1067,6 +1067,8 @@
 	if(KReservedSpace == 0 || KDriveNumber == EDriveZ)
 	    return KErrNone;
 
+    ASSERT(aThreshold);
+
     //-- if the drive has a reserved space, take it into account
 	CSessionFs* session=aRequest->Session(); 
 
@@ -1074,8 +1076,7 @@
         aThreshold += KReservedSpace;
 
     //-- ask the corresponding file system if there is aThreshold bytes available.
-    //-- for some reason it's required to be strictly > than aThreshold
-    return aRequest->Drive()->RequestFreeSpaceOnMount(aThreshold+1);
+    return aRequest->Drive()->RequestFreeSpaceOnMount(aThreshold);
 	}