this might be a stupid question but how does a laptop know when your closing the lid. my laptop will start to hibernate before the lid is even closed about half way.
On the off chance this annoys you it is possible to turn this off, so for instance you could more the laptop without it hibernating. However it is best not to leave it with the lid down for a long time while the computer is still at full power so to speak.
Assuming your using XP, right click on your desktop, select properties. Screen saver (middle tab), then power at the bottom. Then select advanced and change the option for what happens when you close the lid. While I had my laptop I found this a very handy feature, especailly if you are just looking at a connection at the back which requires you to move the screen.