You don't think its too long for pr update.Because its now more than 4 months and old websites are still untouched by recent pr updates. Its too long .. otherwise it took ~3 months usually.
no it's not too long am expecting pr update in September I think there is a lower web activity in this part of year so there is not so great need for update
My site is new in Google (like about 1 month) and still has PR0. Should I receive my PR in September?
PR is a gimmick. So the updates are less frequent but that often happens. Chill out, work on the other aspects of your business.
Don't worry too much about PR and concentrate on building good quality links, it's that which brings rankings and not PR.