I have to manually declare that avast has to ignore tsad.dll that is required for the run of ReGet, a download manager - but only under Windows XP (on P4D), neither on Windows 2000 on PIII nor on Windows 2000 on C2D, the tsad.dll has to be declared explicitely to be ignored.
I consider the concept of warning inappropriate: as tsad.dll is the TimeSink Ad Downloader, not tsad.dll itself should be blocked and considered as virus (or threat), but the ads themselves that tsad.dll is downloading! Or the user should have the choice to block tsad.dll as a prevention or not at first use of it - in the same style that a firewall is learning.
Another way would be to block the ads by the firewall, as a special port is used for them. Nevertheless, the ads should be checked - and not only the dll itself to be banned!