George - the past problem was with some "naughty" scripts that had been hacked onto the Invision servers.
Chris H - after a quick bit of digging, the "Exploit-ByteVerify" is an old trojan/exploit which Microsoft fixed several years ago see this
Microsoft Security Bulletin.
I will assume you have a legal version of Windows and have been very good and got all the monthly patches and fixes from the Windows Update (from the "Start" button or Internet Explorer <Tools> dropdown).
"VBS/Psyme" is another oldie that should already be blocked.
If you have Mcafee (as I suspect), it has a track-record of getting false-positives for several scumware items.
Just for a quick-fix, try clearing ALL your temporary / Internet files (Internet Explorer <Tools> <Internet Options> on the "General" tab, centre block) - the PRF329.TMP file causing the warning is probably sat in the cache and wakes up whenever you come here.