I double checked this, and verified that I start seeing the problem with version 3.6.5 beta. I am running Windows XP Professional Version 2002 Service Pack 1.
Another one has confirmed me that the problem was introduced in 3.6.6. I'm quite confused :-(
Anyway, can anyone download debug version of WinSCP?
It produces trace log to file defined by WINSCPTRACE environment variable.
You may use .bat file like following to run it. Just modify it to point to writeable location on your system.:
Update: I've forgot one important thing: I need the copy of the file in the time when the error message appears. I.e. let the error show and make the copy of the file, before you press any button and send me the copy.
Update2: Version with more verbose tracing was uploaded. The link above has been updated to point to the new version.
Update3: Another update of the tracing.