Mike.. to be honest.. you only have 5 rep points to rep someone..
It's a nice gesture to rep someone, so if you do rep 1 point each time until you accumlate more.
Some sections of the dungeon weld more power.. Bodybuilding discussion is one of the highest while the MISC section is one of the lowest..
If you fully rep someone.. I believe it takes a couple of days for you to be able to re-rep someone again. I believe that is why we get " you need to spread them around"
I had the same issue and consulted costanza about it also.. Granted that was a while ago... and it's from memory..
Hope that helps you out.
Chris