Whenever I want to add some item to my Gnome Panel (by right-clicking task bar and choosing Add to panel), I fail to do that. I run dmesg and I get

002a5e21 sp bfd2e0fc error 4 in libc-2.11.1.so[22c000+153000]
[ 30.964013] eth0: no IPv6 routers present
[ 53.295656] bonobo-activati[1827]: segfault at 1c4f ip 003c6e21 sp bf8f369c error 4 in libc-2.11.1.so[34d000+153000]
[ 53.326405] bonobo-activati[1830]: segfault at 1c4f ip 002b4e21 sp bfc1f5cc error 4 in libc-2.11.1.so[23b000+153000]
[ 2168.660094] bonobo-activati[2219]: segfault at 1c4f ip 001dee21 sp bf9c58dc error 4 in libc-2.11.1.so[165000+153000]
[ 2168.660901] gnome-panel[1428]: segfault at 4 ip 080ad2f9 sp bfb01f00 error 4 in gnome-panel[8048000+83000]

Can you please advise troubleshooting steps to fix this?