I'm rather shocked that my "hunch" on Impulse seems to be correct. Thanks to ReubenElPopo for checking the Impulse forums. I've checked Avast on my two Impulse-enabled computers, and there's been no further virus alerts. I think it's safe to say this is resolved.
The forum mod at Stardock implied that Avast was simply flagging it as a false positive. However the way he responded makes me wonder if that really was the case.
