Mouse clicking through full screen to desktop.
 

When Running the game in full screen, sometimes when I go to click something in game I end up clicking behind the game to my desktop which minimizes the EQ client. I've tried running it in compatibility mode for windows xp service pack 3, but then all I get is a black screen with music that I can't even force quit. Is there anyway to fix this? I'm running windows 7. Thank you

I've been playing on eq live and I have the same issue from time to time.
Usually it's because something I was doing allowed free movement of the mouse off the visible screen. On live that would be when I am placing objects in my house / guild hall.
As for emu no idea but keep an eye on where your mouse cursor is when you notice the issue.

If this issue is like what i have had, you can Alt Enter or Resize the window to regain control of the mouse.

If you are using windows 7, you may be experiences a little thing known as "Aero Peek".
By default this annoying little feature is on, so whenever you put your mouse to close to the bottom of your screen (with a lot of older full screen programs) it assumes you want to "Preview your desktop" and minimizes your game. Unfortunately it doesn't restore it back to full screen.
Extremely easy fix. Right click on your Task Bar, Select Properties, and Uncheck "Use Aero Peek to preview the desktop"

That was all I had to do, hope it's all you need as well.