my suggestions:
1. if u wanna +REP or -REP someone, give a reason (reason can be automatically sent to the member by pm)
2. the pages should be automatically refreshed
3. the ability to add attachments in pm
4. a weekly competition should be held, for most helpful person, i.e. beside the REP and number of posts boxes, a new box should be added showing how many questions u answered etc.
and that's it, dont change the design, its fab, but a new logo would be nice, hope u take in my suggestions,
thanks