The crash while uploading is 100% reproducable for me:
I have a program running on the DigiX, which is sending status messages via SerialUSB and a third party terminal program (e.g. putty) connected to it.
At a give point I press reset on the DigiX, the terminal program doesn't realise, that the DigiX is gone.
Now try to upload from the Arduino-IDE and the IDE will crash!
When you try to upload before resetting the DigiX, the IDE realizes, that the COM-port is busy. After that, the COM-port seems to be in an undefined state.