I can confirm that the monorail package is a culprit for the crash. I tried by uninstalling apps one by one based on niche's list and finally after removing monorail, xournal worked again.
I am so amazed with xournal's power with such small footprint. Being able to annotate PDFs smoothly on the fly without using any bulky resource eater (esp. those on windoze..) makes this a killer app. Thank you and please keep up the good work!