Well 3proxy might not be false positive, but it's not a virus either - it gets detected because some actual viruses have a proxy function. 3proxy is not a virus.
Also I had a similar problem with CHKDSK on WinXP - it was really annoying so I turned it off with a command:
chkdsk /x drive_letter:
Usually it runs that check after some time to ensure integrity of the drive. If your HDD has bad sectors it might run that thing every time...