Xournal and Jarnal both flaky (on Lenovo X220t, under opensuse 12.2)

I tried out both of these today, having some years ago used Xournal to mark up PDFs while lecturing (that was on a Lenovo X61, under opensuse 11.?). I found Xournal worked quite reliably.

Today I played a little with Xournal and Jarnal, and I think the appropriate word is “flaky.” After a promising start, both programs gave me the experience of kicking into an unresponsive mode, drawing me lines when I wanted only to use the style to access a menu item. I was forced to reboot (could not control the computer either with pen or mouse). This suggests it would be foolhardy to attempt to use the tablet facility for lecturing. Has anyone had similar difficulties, and overcome them? Yes, I am rusty, but I didn’t do anything one wouldn’t be likely to do in everyday use. Thanks, JW