Oh dearly me chuck, is there something particular that you do at the weekends that you don't do during the week that could be triggering these thoughts?
Do you drink more or put yourself in situations where you are around lots of smokers or is it just a phycological thing do you think?
When i quit i tried to change my weekend routine to avoid situations like that, i started running again which i reallyed enojy and i TRIED to drink less (although that maybe didn't go so well! )