That does not make much sense. Anyway, try to uninstall WinSCP. Make sure that the ...\WinSCP folder is gone completely. Reinstall 4.1.2, which should include up to date translation.
That's exactly what I did, a few times.
To be sure that WinSCP ánd the WinSCP-folder really were uninstalled/deleted, I restarted Vista, reinstalled 4.1.2 (Dutch language) -same error. Did the whole procedure again, but with English language this time, and still got the error. Tried it again, 4.1.1 (Dutch language), error popped up. Finally I repeated the whole thing, installed 4.1.1 (English) and that did it.
I did the same procedure each time: uninstall WinSCP, delete the WinSCP folder, restart Windows, reinstall.
The only thing I can think off now is after uninstall there remain parts of WinSCP in the register.
Ow, forget to mention: thanks for the quick reply, both of you!