I'm having similar trouble. I haven't yet tried it from the command line, but here are my symptoms:
The "Write Image" dialog takes several minutes to appear, in the interim between when an the "write to disc" button is clicked or a .iso file's context menu's "write to disc" entry is selected, CPU usage goes up to 100%. When the dialog finally appears, the speed 0.0x is selected. Clicking the 0.0x selector triggers another long wait. When the list of speeds finally appears, it's populated with hundreds (if not thousands) of entries, starting with a "0.0x" at the bottom, followed by about 20 more "0.0x", followed by about 20 "0.1x" entries on up. I threw my mouse to the top of the screen to attempt to get to the fastest speed, but after several minutes, I was still only at "8.7x", which I selected and proceeded to burn. The burn appears to have gone OK, though it was not at 8.7x, it was closer to the max speed my drive supports (a burn of the knot-2 CD took about 3-4 minutes). -- [edgy] nautilus-cd-burner uses 90% cpu making it unusable https://launchpad.net/bugs/57174 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs