I have a Samsung SyncMaster P2470HN monitor and every time I plug it in and set it for use it starts to blink intermittently every 2 seconds. First it show the workspace, then it blinks and shows the message "Check signal cable", then it show the workspace again and it goes on forever (until I unplug it). Now I'm using 32 bits Lubuntu 12.04, but I used to have the same problem while on 32 bits Ubuntu 12.04.
My video card configuration:
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)