USBClient:
This has been noted when a recording cannot be played back from the supervisor.
There was a problem with the update of version 1.5.2.1. The install replaced
the existing shortcut with one that had a blank entry in the "start in" of
the shortcut. GSM files would then be written to the documents and settings
folder for the windows user.
If so, extract the USBClient.exe(from the update file) and copy it over the
existing USBClient.exe, you will not get this error.
Card Server:
This has also been noted once with card server recordings. Under investigation!