HDMI Laptop to TV

Can anyone help with this please ?
Toshiba Satellite Windows 7 Home 64 bit connected to Sony Bravia TV via Hdmi lead,picture on TV is fine until I close the Laptop lid then picture on tv goes into a small window with black surround.
I've set laptop to do nothing when I close the lid.

Thanks in advance.

Select External display as primary screen with correct resolution
reset to laptop display as primary and resolution when disconnecting.

Don't close lid fully. My Dell Studio has no picture or sound from the laptop once HDMI cable is plugged in.

Thanks for the replies folks,I've played around with display setting 'til I'm blue in the face so leaving the lid open a crack seems the only option.

Thanks again.