Comment 0 for bug 421048

On logging in to Ubuntu, sometimes there are randomly placed black dots on the screen. I have seen this problem on an old Hardy install on a PPC and on my current Intrepid install running on an Intel Q9550. Another machine with Intrepid on an Athlon has never exhibited this problem. All were 64-bit installs.

The dots are black pixels and not window or virtual desktop dependent (they remain in the same place regardless of what the OS draws on screen). Occasionally some may appear or disappear and sometimes they all go away and return at random times.

I have discovered that simply logging out of the session and logging back in to X clears this problem (I have had many weeks of uptime after this, so am certain that it is a permanent fix).

The dots do not affect any function of the OS, and can be fixed (for me) by restarting X (as above), but they are an unnecessary ugliness for those users that are affected.

My guess is that the issue is with the X server - but I am not sure how to verify this.

There is a thread (784045) about this on the Ubuntu forums (http://ubuntu-ky.ubuntuforums.org/showthread.php?t=784045)