External monitor on DVI problem - sometimes off

[Malysh]

I have a problem with external monitor.

Installation: T61 (Nvidia 140M) - Advanced mini dock (DVI) - DVI D cable (dual link) - ext monitor ViewSonic VP2030 (1600x1200)

Sometimes after reboot I cannot see external monitor at all: if I try to expand desktop on it (using Windows or Nvidia Control panel), nothing will happens, it remains black. Reboot cleans this.

This behavior occurs only if in BIOS setup option "Boot screen" is set up in "Thinkpad LCD". If I set "DVI+LCD" everything MAYBE OK (it can boot not in Dual view, but in clone mode), and after reboot it could sometimes reset back to "Thinkpad LCD".

BIOS version 1.26 (the newest one), Nvidia drivers also updated.

What can I do to solve it?

[Malysh]

Strange, I've tried to unplug and plug the DVI cable again - it works immediately!