I have read on glipper mailing list that the glipper maintainer has left the project so glipper is no longer maintained :(
Anybody with Python skills is welcome to joint the project and continue work on this small but essential and cool little project. I can't imagine day-to-day work on Gnome desktop without this fabulous tool.
I can't wait until somebody with Python skills comes along and makes this project shine again...
Try parcellite - an alternative to glipper:
yum install parcellite
Thank you Martin for your comment regarding parcellite, and also thank you Christoph for fixing some glipper bugs, but it still has this issue with crashing on startup.