I'm actually having the same problem. I have a huge hydro damn with 6 8-level towers. They all come together and I've done extensive research into the power supply (different wires, etc.) and when I first built it the the power output was awesome. After logging off and logging back in though (and restarting the SMP server) there's no power being produced. I've trouble shooted in-game by:
-Wrenching and then replacing the watermill,
-Replacing the wire
-Bucketing the adjacent water and replacing
(All while using the EC Reader to check the status)
Simply put there's just no power coming from the mills anymore, but since it's not crashing I don't have an error file (sorry).
I've read other places that people had trouble with the Windmills doing the same thing and they fixed it by deleting the sound file, but I wanted a sanctioned result before going and messing with the innards.
The most recent server files are being used IC v1.15 & MC v1.81, and (aside from some crashing that was fixed with the xy.class) everything else has been working great. It's a phenomenal mod and I really appreciate all your effort. Hope to have the industry back up and running soon! 
GTAerrow
I had solar panels connected to an MFE which was filling last night but today is completely empty. The wiring was glass, only like 12 blocks away. The things i tried were just reinserting the .class files for MCforge and modloader into the minecraft.jar file (btw thanks for the speedy reply)
