TC 7.5x USB Port connection bug

[DrShark]

I reported that bug in July 2010 to Mr. Ghisler by e-mail, but he couldn't reproduce it. Now even I don't have a second PC (with WinXP) to reproduce the bug so I post it here in hope someone sometimes will encounter it.

To reproduce:
Try to Sync two dirs with the same files on different PCs connected via USB Easy Transfer Cable.
Result:
Each time in compare results TC gives a random files marked as "?".
For some reason, Sync tool cannot compare a number of files (primarily a files with small size).
Both server (in window) and client (tcftp.log) reported next error for the 'failed' files:

Code: Select all

XMD5 C:/somedir/somefile.html
GETMD5
ERROR: 0

Conditions:
1) 1 meter long DataLink USB to USB STLab (U-440) Windows Easy Transfer Cable
2) TC as server: Windows Vista SP2, TC as client: Windows XP SP2 (or vice versa)
3) (maybe optional) Antivirus installed (KAV; later KIS, versions 2009 to 2011, but the bug appeared even with disabled live protection).

[ghisler(Author)]

ERROR 0 means a connection loss - could it be that a virus scanner stalls TC on one side? There is a timeout in the port connection of several seconds, if the server side stalls for several seconds, the connection is lost and re-established with the next file. This can happen when it takes a LOT of time to open the other file (during the read, the server sends keep alive messages to avoid that).