On Fri, Aug 19, 2011 at 12:53:46AM +0300, DiP wrote:

I found where it is.

It seems to appear on my desktop box when I connect cams to the same bus.
Two connectors next to each other.

But on the notebook it does matter. Any bus, any port.

Problem still alive with a kernel 
3.0.2-pf-di #1 SMP PREEMPT Fri Aug 19
00:21:22 EEST 2011 x86_64 Intel(R) Core(TM)2 Duo CPU E8200 @ 2.66GHz
GenuineIntel GNU/Linux

Sounds like a problem worth reporting on the relevant mailing lists. If
you have the time and patience, bisecting the (possible) bug may be useful
(see http://www.kernel.org/pub/software/scm/git/docs/git-bisect.html).

HTH,
	Jonathan Neusch?fer