@BitFlipper:Thanks! Can't believe I didn't pick that up - must be getting typo blindness!
I don't understand the crashing issue yet - sadly I am away for the next few weeks so it's going to prove difficult but I will endeavour to fix. Does anyone have any clues as to what might be happening? (I don't get the issue on any of my own or families machines)
EDIT: Fixed the typo, thanks!