Hallo,
Mac users can try this latest build: http://forum.avast.com/index.php?topic=54952.0
New features: auto-scan timer, path exclusions/patterns (useful for TimeMachine), incremental updates of both VPS and the engine (both on the fly, w/o the need to even close the app itself), verbose/suspendable warnings, hidden-mode, better asynchronicity, less invasive pop-up windows, background sessions, latest engine, 10.6-related fixes…
Still supports old PowerPC platform, Intel platform, MacOS 10.4, 10.5 and 10.6, 64-bit system/xnu compatible. License files will be kept active and you can return back to the old version anytime simply by re-installing the present package. Worth a try 