It is small, and not obnoxious. It reminds me of the old nag screens on shareware, except in this case I paid the registration.
It just feels like a kick in the pants to be asked on every screen to do something, both of which I already did.
"Please consider registering and becoming a Supporting Member"
If you cant code it to only show to non-supporters, at least consider rewording it. (or get better coders)