was calling screenmain() before executing the python script which meant it was never executed (therefore no crash :) )
Moved screenmain() back to the the end of main() and added a TESTBASELIB_BGMODE which checks for G.vd and uses the scene layer if its not there. Of course python should not be running stuff that uses G.vd :/
Also made python scripts stay attached to screens when LOAD UI is disabled. This means you can load a new blend file and the python console can stay open, has been tested for a while in the apricot branch.
db18b47be5