i need kwin effects but when i enable it there is hang , with compiz until now everything is OK
I can't remember if there was a similar flash problem related to an nVidia driver update for your series of cards (nvidia-current). One last thing you might try is to downgrade the nvidia driver, if
it's possible. It will depend on whether the previous driver is still in the repos. To see, open Synaptic. Find the dkms-nvidia-current
package and highlight it. Then, click on Package in the upper left corner of the Synaptic window. If Force Version is not ghosted out in the drop down menu, you can downgrade the package by clicking on Force Version and selecting the version number to install. Otherwise, your currently installed package is the only one available.