I set up an incubator and opened it's GUI. Its power gauge (red thing at the left) displays -15536 / -15536 RF when I hover my mouse on it. And the little battery icon with an X on it says "Missing RF". The thing works though. Just showing the wrong RF value.

Please confirm this is still an issue on the latest build. I can't recreate it.

It seems to be a multiplayer issue. I lauched my modpack (with your latest recommended - I think the 97 - build) on a ssp world to test it and the RF was 50000. Same thing with my smp game, -15536 RF. It's hard for me to test your latest build in smp but I will try.

Oh right, SMP hates anything over 32767 using the default handler for sending gui updates. Now I remember why I was using a custom packet handler before... switches back