Does debian carry any patches? if so, can you reproduce this with a vanilla X server? I just vt-switched about 50 times with 1.12.99.902 but it doesn't happen here.
What desktop environment is this? something is trying to change the property after the VT switch, so I'd need a similar setup here.
Finally, if you can reproduce it easily, can you try running X through valgrind to see if you get any invalid writes?
Does debian carry any patches? if so, can you reproduce this with a vanilla X server? I just vt-switched about 50 times with 1.12.99.902 but it doesn't happen here.
What desktop environment is this? something is trying to change the property after the VT switch, so I'd need a similar setup here.
Finally, if you can reproduce it easily, can you try running X through valgrind to see if you get any invalid writes?