Laptop freezes when lid is closed.

When I close the lid to my laptop, it freezes the entire system. I am running an HP Compaq 6710b with Ubuntu Linux as the only operating system. I am just changed to Linux yesterday, since I was getting tired of all the issues with Windows, and so far have been thrilled with the OS. This is the only major hangup I've come across. I tried playing with the power setting, so that it "does nothing" when I close the lid, whether on battery power or on AC, and it hasn't fixed the problem. This is a major issue for me, since I do a lot of downloading and stuff overnight and need to have the computer able to continue it's work while I'm sleeping. If anyone could help me with this, I would appreciate it, I am a complete noob at running Linux.