TV bad why?

I've read in a few threads recently that it is bad to have your TV in the gap between your speakers. Why is this? Reflection from the screen? My room doesn't really allow any other set-up...my speakers are approx 8 feet apart with the TV on an AV stand about 3 feet behind and diagonally away about three feet for each speaker. I'm happy with the sound but just interested as to why this is not ideal. And to be frank don't fany lumping my 28inch widescreen about in order to tweak. Thanks in advance. Ben