Here is what I have discovered.
I use the HJU mode(or gray skin background) when I'm on HJU. Ever since the last HJU shut down or maintenance, everytime I get on HJU, even though I have the HJU mode on, the background is white with a grey outline.
Anyway, when this avast problem came up, every thread I'm on including has the warning come on six times. However, I have discovered that if I click on one recent thread links on the right hand side of the screen, not only does the full HJU mode(grey) background come back full time until I leave HJU, the avast warnings stop completely.
I don't know if this helps or not but that is what I see when I'm on here.