Oneworldboy - Why would you not consider Houstons to be an official chain? I think that they meet the very definition of a chain:

"a businesses under one management or ownership and offer similar goods or services but are found in different locations"
see: http://encarta.msn.com/encnet/featur...fid=1861596080

p.s. - Here is their website: http://www.houstons.com/