I have the same problem with ubuntu 11.04 fresh install. Don't know if it's a display controller issue, but symptoms are the sames as described by rix.
My display controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 03) -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-intel in Ubuntu. https://bugs.launchpad.net/bugs/782855 Title: missing pixels (horizontal lines) in font rendering _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp