Images No Longer Open on 2nd Monitor

When I opened an image in Photoshop CS3, it would appear on my second monitor (which is larger and better quality). Ever since upgrading to Photoshop CS4, I can't get any images to open in that second monitor -- instead they open in my main monitor under all my panels, and I have to drag them manually onto the second monitor.

I know it's a minor annoyance, but I open dozens of images a day.

Anyone have a clue how I can fix this issue?

Thanks.

There might be some help in this thread;

<http://www.adobeforums.com/webx?7@@.59b70cf4/3>

That's the thread I should have read first! Thanks for the pointer.