Cant re-boot if external monitor plugged in

[rocketjacket]

I am having problems on boot/re-boot - mac book doesn't reboot if external screen is connected.
Its a 15" 09/Running Mountain Lion

I just get a grey screen. I have to unplug the external monitor (mini dvi) and plug back in.

Any ideas?

 

[jarodcore]

Solution?

I was curious if you ever figured out what it was that caused this. I've had the same issue since Lion, and now with Mountain Lion.

I'm running dual monitors (my native Macbook Pro 15", and an external Samsung LCD). It's connected via Dynex Mini DisplayPort to HDMI adapter.

If I restart the MBP with the external monitor connected, I have no problem. It only occurs if the external monitor is connected and I boot up from a Shut Down.