Avast & TBP & FFP

Using Sandisk U3 and TBP & FFP, not U3 versions. While in Thailand for a month found many many public computers which were infected with win32/Brontok.A worm. This resulted in auto name change of several files.

Now cannot open TBP, and cannot open many mail files in FFP. Running TBP on the desktop, NOD32 detects the worm plus I cannot open several msg files. In essence have lost several msgs that needed to be kept. And FFP was rendered useless for the last week of the trip.

This was caused when Avast detected the worm and changed a file name before I could save a file under another name (perhaps it was already infected from a prior computer, so that wouldn't do any good anyway!). Actually, the worm was detected the moment the thumb drive was plugged in and Avast ran, so don't know why/how the infections occurred since I quickly removed the drive -- even if I wasn't able to turn it off.

I was under the impression that Avast would detect the worm in the host computer and simply advise me to shut down the thumb drive before using it -- but obviously this isn't the case.

Now that a month of "kept" & "pending" msgs have been lost, and FF was useless for some time I'll need to wipe the portable and reinstall. What should I do the next occasion which will be in January?