In reply to:
it sounds like your amp is trying to protect itself -- maybe just from bad music. Actually, I have to admit I never heard of audioslave so I went and downloaded a couple of samples -- pretty cool! Anyway, from the samples I heard, it doesn't sound like its the kind of music that has a lot of spikes or peaks (i.e. high energy transients). Does the track you were listening to have a lot of sudden bursts of energy (quick transitions from soft to loud sounds)?
LOL - Glad you at least checked it out before you wrote it off
... Anyway, no the song I was listening to was a simple song with very little variation (spikes or peaks). The 8000 does not say it is rated for 4ohms, but in every review/opinion I read before I bought it was fairly clear that 4ohms worked fine and posed little/no problems.
On a side note, I decided to replace all of the wiring (small sanity check) and havent heard it since. Hope that was it!