Hi Robert (with note to Christian Henz), Thanks for your reply here, also, and for the suggestion. I also have the Radeon 9200. I just went out and got the latest fglrx driver --- just before seeing this message in fact. I was previously using the Radeon drv. Previously I was a little apprehensive and worried about using fglrx and had put it off (since January!) but decided that perhaps a change in the DRI module might be an improvement. So I was glad to see that you had also installed these drivers. fglrxinfo: display: :0.0 screen: 0 OpenGL vendor string: ATI Technologies Inc. OpenGL renderer string: RADEON 9200SE DDR Generic OpenGL version string: 1.3 (X4.3.0-3.11.1) <<<<<--- new one MusE now will not lock memory under any circumstances I have tried, even with your suggestion of limiting the VideoRam. WARNING: Cannot lock memory:: Cannot allocate memory WARNING: Cannot lock memory:: Cannot allocate memory midi thread 1652 _NOT_ running SCHED_FIFO qjackctl still locks up the system, even with your suggestion of limited VideoRam. With ulimit -l 128000 or anything else qjackctl works just fine. MusE won't lock memory with either unlimited or 128000. So, I would conclude that IF MusE would be allowed to lock memory, it would lock my system up just as qjackctl does when ulimit -l is unlimited. I'm not sure how much I really want to pursue this. Linux isn't a real-time O/S, so trying to make it act like one is probably doomed --- at the very least, it's complicated. (Note to Christian: I've seen postings with troubles with 2.4 as well, so it's not just 2.6. The postings I saw were with respect to other programs, but still memory locking stuff.) Thanks again and best regards, Dave.