The situation is:
If you are running 4.1.280, you’re ok.

The people with automatic updates had this update chain:

something → 268 (Thursday, 18th) → 268 (phony, Friday, 19th) → 278 → 280.

People without automatic updates and version 268 had:

something → 268 (Thursday, 18th) → 278 BUG BUG BUG BUG :-[

But now, they’re ok (at least we hope) with this chain:

something → 268 (Thursday, 18th) → 280 okay, okay, okay. ;D

even with
something → 268 (Thursday, 18th) → 278 BUG BUG BUG BUG → 280 okay, okay. ;D

The problem lies in two bugs as I explained here: http://www.avast.com/forum/index.php?board=2;action=display;threadid=1410