As described in the KDE bug tracker [see link] the USE-flag "jingle" causes kopete to frequently crash on startup or when adding a jabber account.
Because of comment #10 ["Jingle is unsupported. Don't expect a fix for this soon."] I suggest to mask the jingle USE-flag.
*** This bug has been marked as a duplicate of bug 223535 ***
actually I think this is a separate bug, as
1) kopete compiles fine with jingle but crashes during runtime
2) I'm using gcc 4.1
3) the problem is not limited to kde-base/kopete-3.5.9 but also effects earlier versions
I didn't see a patch in upstream bug so i have to close this as i don't think it will be fixed in the future. The only thing you can try is update to 3.5.10