Xserver start delay on ATI Radeon X1050

[Przemysław Kędzierski at freedesktop.org]

Hello

I bought ATI Radeon X1050 card, made by MSI.
(It is PCIE card, lspci shows two devices 1002:5b63 and 1002:5b73)
I have problem, small but nasty,
Xserver during start blanks monitor and waits 30 seconds.
After this time it runs without problems.
I'm running a Debian unstable and X version 7.1.1, from Debian package.
I tried to find reason of this behaviour.
I used strace on Xserver and added some RADEONTRACE() in radeon_driver.c.
Xserver waits in RADEONWaitForVerticalSync2, when it enters first time.
I have only one monitor plugged, one Monitor and Screen section in 
xorg.conf,
so why does it wait?

Thank you
Przemek Kedzierski