I added one graphic card more.
Seat 0 works, but seat 1 doesn't. When I try to launch seat1 I get an error about missing screen 0.
Also I get a warning about no device at 02:10 PCI bus, but according to lspci it is correct:
01:00.0 VGA compatible controller: nVidia Corporation NV43 [GeForce 6600/GeForce 6600 GT] (rev a2)
02:0a.0 VGA compatible controller: S3 Inc. ViRGE/DX or /GX (rev 01)
I rechecked xorg many times, but I cannot find problem.