Hi, I'm experiencing the rotation bug as well (so far I have only noticed client side ~ visual bug, all machines are still working properly). I have installed a bunch of plugins on the server, but after permissionsEX and MultiVerse it started doing this. Also players are unable to change redstone behaviour in ic2's "battery" units, don't know if it's somehow related to this thread's bug.
I hope IC2 guys change their minds and fix (their?) mess..