Also I used to have a similar problem on ubuntu 11.04 but syslog file used to have a lot of "i2c i2c-10:send bytes: error -110" line which is still printed in syslog file but rarely and the screen stopped flickering when the line " echo 0 > /sys/module/drm_kms_helper/parameters/poll" was added to "/etc/rc.local" which is still there
