Kerbal Space Program

My framerate drops significantly after every time I switch from a craft to tracking station or space center, or if I revert to launch.
When I revert to sph/vab and launch again the problem is reset.

I managed to replicate this problem not only with fresh vessels landed in space center, but also on vessels cheated into kerbin orbit.

This is with freshly downloaded (from steam) stock 1.5.1 + MH.

How to replicate:

• Launch a new craft
• note your framerate in console
• revert to launch or go back to tracking station / space center and switch back to the craft
• note your framerate again, it has dropped
• revert to VAB/SPH or quit to main menu and relaunch the craft
• framerate should be good again