24 inch LED Cinema Display Slowing the Computer internet Connection

I just purchased a 24 inch display for use with my 13 inch MacBook Unibody and when it is connected the internet response slows down considerably, possibly 1/2 speed. When I disconect the display it opererates at normal speed again. Has anyone else had this happen? Are there any settings that need to be changed, etc?
Any suggestions would be appreciated

Thanks
Mike