You know, I always thought it was mostly people from the North of England that say "sat" as the present tense instead of "sitting". Not gonna lie, it drives me absolutely up the wall whenever I hear people say it!!!! I mean you'd never hear someone say "I'm played tennis" so why on earth do people say "I'm sat"? Just one of those things I've never been able to get my head around despite coming from Manchester where quite frankly folk look at you like you're some kind of alien if you do come out with the correct tense. Sorry for rambling but it's just one of things that really bugs me lol.