Well you are at the wrong IC2 Classic... Tekkit legends is with my version... And what you are discribing is that the Generator is overpowered...
Thats causing it... Simply go a little bit lower or place a couple blocks near the generators so that they do not produce so much power...
Sooooo, it's not a bug?.
I'm no expert with that but, any suggestions how much and where should I place the extra blocks?
I also have the windmill tower of 4 mills in a + shape with the top mill at 181 height if I'm not mistaken and bottom at 165, and 4 blocks; 20 in total block above it all as suggested on one post I've seen. And also on that tower the generator happenes to apear. Dunno if it means anything but maybe worth mentioning.