"\\servername\\filename\data\m\mudaaaaa.b" sound like one of the files that make up a sourcesafe archive. Its sound like in some way that the archive is corrupt. Could it have been when you've moved things something was missed.
There is a advised maximum size for an archive I think its around 4 MB. There is also a job you should run against Sourcesafe on a regular basis to prevent corruption. This is called Analyze.
Try looking at this page as well:
http://msdn.microsoft.com/library/de...ml/vssbest.asp
It think it still true for later version of SourceSafe.