Copy-paste is broken in KDE?

[Yuri]

I am seeing occasionally that selected text isn't being copied into the 
clipboard and isn't available for subsequent paste (with the middle 
mouse button).
In most cases it works, maybe in <1% cases it doesn't,  still enough to 
make it annoying.

Also for example I am not able to copy the selected text in the 
previously sent message in skype-2.0.0.68 (Linux app) to the clipboard 
and paste it to thunderbird.
But if I first paste it to the shell window and copy again it then 
pastes to thunderbird ok.

Anybody observes these kind of copy-paste problems?

Are they known issues?

I am using KDE 3.5.8 and FreeBSD 7.0-STABLE

Yuri