One way to lock X instantly, which is very repeatable and surprizing that it got past regression testing, is to simply launch openoffice and pull up the open file dialog.
I've reported this with older drivers, and the newly released one (topic of this thread) has the bug as well.
Please see thread http://www.nvnews.net/vbulletin/show...p?postid=96556
for more info.
On a good note, the performance of the new driver is incredible!
With my measley GeForce2GTS64M card, I can run UT in 1600x1200 with very smooth performance (1400x1050 was pushing it before).
Unfortunately, not being able to run openoffice, or just have a stable X, means I have to rely on the non-accellorated nv driver.