User Names

Sometimes I am sad enough to sit and watch the names on the bottom of the screen all moving around as people join and leave - but can anyone tell me why the users who are already online are moved about too - is there a method to the apparent madness of the "user name dance"!!!

By the way -

ITS MY 500TH POST - WAHAAAAAAAAAAAAAAAYYYYYYYYYYYY

:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D:D

GET IN THERE!!!!!