I don't know where then I have just visited the site and no alert
Now I'm using firefox 3.0.10 with NoScript so scripts don't get executed but that shouldn't stop avast alerting as it doesn't rely on the script running. Given that I have just allowed the site in NoScript (not generally advised) and still no alert.
I have checked the page source code and I can see nothing obvious, certain;y not an iframe, of a obfuscated script (which is commonly used to create and execute an iframe). So I'm at a loss.
When did this happen ?
They might well have had reports of the detections and resolved it, that however is speculation on my part.