Due to the Forum upgrade there was a time when avatar size limit was not in use.
Incase you had your avatar (the porsonal picture on left side of your post) size set to something larger than 85x85 it won't show up anymore.
The avatar size limit was taken back in use because they were just getting bigger and bigger which pretty much messed up the format of the topics. Now everything nice and tidy again in a straight line.
So, if you've been wondering why your avatar won't show up, the only thing you need to do is resize it to 85x85 max with an image enhancing program such as Adobe Photo Shop for example.