Dock disappearing when using the Show Recents menu item? I just discovered that if I Turn Hiding On and right click on the iTunes app in my dock and press Show Recents, then my dock will no longer appear when I move my mouse to the bottom of the screen until I log out and back in. I have the latest version of Lion and I was wondering if this was only me.
This may be only you, which could be an issue with the preference files, etc. 

Show recents (with a Dock that hides) for me shows the transparent dark screen, and whatever icons that should be there for that app, and shows the dock fully available. 

Once clicking on the desktop though, to get out of this mode, my dock hides again as it should. 

I would recommend removing the Dock preferences, which is located at ~/Library/Preferences/com.apple.dock.plist, and then restarting the dock. 

You should open the Terminal (/Applications/Utilities/Terminal.app), and then run:

rm ~/Library/Preferences/com.apple.dock.plist


then run

killall Dock


to restart the dock. You may have to set up your dock icons again, but this may help the dock not showing back up after using 'Show Recents'