pasting xbuffer not working in many apps

[Die Optimisten]

Hi!

Debian 7.11
mouse-pasting of xbuffer in iceweasel, openoffice (and some other 
X-apps) doesn't work,
while pasting into xfce-terminal works instantly.
Copying/selecting _and_ pasting text INSIDE icedove works as it should.
How's that possible?

Can someone correct this?
I also see that pasting text to openoffice (just some words) often needs 
minutes.
0% cpu, no swapping

thank you
Andrew
PS: PLEASE also add me to every CC:, I#m not in this mailinglist!