Using the latest version of Big Reactors, 0.3.4a, the clutch disengage and engage buttons, in the turbine controller GUI, do not work. The turbine its self works just fine in all other ways though, the clutch just can not be disengaged to speed up the turbine quickly.

Yep. Bug in my network code. Thanks for the report, I'll get 0.3.4A2 out soon.