Fedora 15 - copy and paste problem

[fedora]

Hi all
when it came to upgrade gnome within Fedora 13, i could no longer use 
the mouse-middle-button to paste the clipboard: i had to click both left 
and right mouse keys.
OK, thats past.
Yesterday, however, i installed Fedora 15 and now neither of the keys 
work: when i strike text with the right mouse key pressed, no text is 
copied to the clipboard, and when i either push both left and right keys 
of the mouse or i click the middle mouse key, nothing happens, no 
clipboard copied to the input line.
the only way i can do copy-and-past now is to strike the text i want to 
copy and then use the edit menu of the respective application, and click 
copy there, and then move to the input line and click paste in the edit 
menu of the respective application.

am i missing something with the mouse-key emulation in the X server?

How can i get back to the old Unix style behaviour?

thansk for all hints.

suomi