I've had a couple of people get locked out of the forum when changing their emails or passwords just recently, and I don't really know why. I'm going to keep an eye on it.
If this happens to you, DON"T PANIC! The webmaster doesn't have a vendetta against you*, and I do get a email from the system every time it bans someone with a link to reinstate them. You will most likely be back in good favor before the end of the day.
* Not valid for members named Steve, or certain instances of Russ.