So I recently tried updating cgminer on two of my windows machines from 3.12.0 to 3.12.3 that are connected to multiple hashfast babyjets, and whenever I try running 3.12.3 cgminer just crashes on startup, yet 3.12.0 works...

I strongly advise people wait till they have new firmware as the new cgminer code is optimised around it and vice versa.