diff -r 0ff03867bdb6 -r 39b39e1a406e userlibandfileserver/fileserver/sfile/sf_utl.cpp
--- a/userlibandfileserver/fileserver/sfile/sf_utl.cpp	Wed Jul 21 14:46:58 2010 +0100
+++ b/userlibandfileserver/fileserver/sfile/sf_utl.cpp	Thu Jul 22 16:46:39 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);
 	}