Parts relocking after purchasing??

[sedativechunk]

I am on the latest version of KSP on Steam on Windows 8 64 bit. I only have a couple mods installed, one is a command pod and the engineering redux, that's it.

For some reason, certain parts (one in specific the "launch escape system") relocks after I purchase it! I am playing the full career mode with science and funds. The science unlocks the part, but the funding. I will buy the part and unlock it and it will stay that way until the next time I restart KSP and relaunch the game. The part gets "locked" again and I have to spend funds to buy it again.

Why is this happening, is there a way to fix it on my own?

[Requia]

I can duplicate this on my modded install but not a fresh unpack of the zip. Try pulling out what little mods you have (worryingly, the only one we likely have in common is Engineer).

[Requia]

Stating a whole new KSP folder then reinstalling mods seems to have fixed it. PITA.