I had no idea they could be CC'd. Fear works too? Last night I got to the point where I could take the shaman down to maybe 40% before I ran out of interrupts and had to just watch him heal back to full. I thought it must be a gear check, that my DPS wasn't heavy enough to burn him down, or something. I probably should've at least TRIED fearing ... I mean, the fact that any interrupts work at all should've suggested that these guys aren't standard bosses!

Thanks for the advice! Awesome.