That might just be minecraft being minecraft, I'm not certain, but the lighting engine is not known for being a very good one. similar things have happened to me on several occasions without IC2 machines being in the area
From http://www.minecraftwiki.net/wiki/Controls using some of the F3 + key commands might be able to force the engine to update or reload and repair the visual strangeness.
I've had issues like this a few times but never been able to pin it to a single mod, although never seen it localized in front of anything particular, just on walls and floors.
