When I registered on I-Club like 3 years ago, I was under the impression that you had a "username" that you used to login to the site, and a seperate "member name" that would show up with your posts. I used "sperry" as my username since it's the same username I've had on lots of systems at school/work. Then I found out that the username is your member name, and learned to live with it. As I started joining other boards, I kept the same name so other people that cross-breed on the boards will recognize me.
I actually prefer it now, since all the people with names like "02WRX_BADASS" and whatnot look like jackasses when they sell the WRX and buy a Honda or some crap.