Originally Posted by Chalmbers
Was having the same issue as homeofpoe.
Uninstalled Ubuntu Package and installed through binary and its working great, thank you!
This generally resolved the problem for me, aye. Though I've noticed from time to time it still occurs - however, it does so with more apps than just Calibre, such as Firefox. This leads me to believe there's some deeper issue indirectly related to some Calibre activities.
The binary did make a significant difference for me though. Occasional xserver crash versus regular crashes. So, Calibre's generally usable for me.