I've recruited a lot of people over the level of 15, although when I check their levels on the guild list they show like level 1's, 5's, 10's etc. I think that the server as a whole hasn't updated everyones level when they are accepted into a guild. This is probably why theres a few members showing under level 15. I check carefully before recruiting anyone, which is why I thought this was causing it to happen.

YES this is very important. never kick anyone just by the lvl that it shows in guild. ALWAYS whisper then and shift click thier name so as you can reveal thier true lvl to you. and wa la!