I will bet my incredibly devalued house that this is a false positive. Here's why:
1. Updated 2 PCs manually (this is why I don't do automatic virus def. updates) and rebooted. The PC running Win XP Pro immediately showed avast! warnings for the above trojan for apps I've been running for years (e.g., Atomic Clock Sync, PowerStrip, MagicDisc, Net Activity Diagram, AutoGK during a boot-time scan.... yeah, I canceled that nonsense immediately)
NB: avast! running on Vista Home Premium DID NOT throw up a boot-time warning on Atomic Clock Sync, even though that app starts at boot, but a manual scan of Atomic.exe claimed the trojan was present... so, avast! on Vista failure???
2. A PC that is running an earlier version of the VPS file (pre-Dec. 3, 2009) displays no boot-time warnings, nor finds said trojan on a manual scan of Atomic.exe.
Thankfully I only moved a few things to the Virus Chest, but restore didn't do much (said it restored successfully, but attempting to start Atomic.exe didn't work). Also couldn't copy the Atomic Clock Sync installer from a NAS to local HDD until disabling avast's on-access scanner(s). Install was fine after that, of course.
Until this is fixed (hopefully on Dec. 4) the solution is No Action or Continue when that trojan is "found." May be prudent not to ignore claims of other viruses found, however.
Hope that helps.
Helluva first post. forum.avast.com was so hammered I didn't think I'd be able to register ;-)