I got the error message "Cannot write output file. Not enough room in heap zone" when trying to save a large (hmmmm very large) gsm-object.
I checked the www and it seems it's a Mac OS problem. I use a PC...
Probably it's my 512 MB RAM which is to little (or more self critical, my model is tooooo big). If it's only a Mac problem....my computer has gone schizofrenic.