Comment 229 for bug 1068404

@vuanomarco and @niniendowarior

Until upgrading to 13.10 everything worked fine for me - even with an external monitor attached to my dell inspiron 7520 (with a radeon hd 7700m series card). After the upgrade I got a black screen after logging into unity and was able track it back to this bug: https://bugs.launchpad.net/compiz/+bug/1054257 (compiz opengl plugin crashes with Fatal: glXQueryExtensionsString is NULL for screen 0 message). I have no idea why it suddenly cropped up.
I even reinstalled the entire system to see whether it changes anything, all to no avail.
Right now I am running on an UEFI install with GPT partition table and this last problem might be connected to that (although AMD claims to have added UEFI support to their driver), but I can't be sure, because I had the blank screen problem before reformatting the hard disk.