In case you missed it, Symantec has a newer beta out for AntiVirus for the Palm OS. I downloaded it and have been trying it out. Considering there are only 3 viruses it is protecting against so far, this isn't a must have, but I am sure this will become more of a problem in the future. Seems to work pretty well, with the exception of the AutoProtect feature. I found that on my VDX, it slows some things down to and unacceptable level. While in a program, things seem to run fine, but when switching back to the Palm OS launcher, it takes 3-5 seconds before the icons appear, vs the normal "instant" appearance. I just leave AutoProtect off normally and it seems to run fine. Give it a try and see what you think.
http://www.symantec.com/avcenter/palmscanner.html