Avatar Size[PLEASE HELP!]

Ok so I got promoted to coder on this sites forums Bullet-scape.ultimaterpg.org and we discovered that when you put up a picture in your avatar area it can be any size. This could really ruin our forums if people find out and we can't find an area to change the max size?

As far as I know 150 wide is the default max size limit. However, if someone links to there avatar via a picture host like photobucket instead of uploading it to the forum the avatar will keep its original 'large' size in some areas of the forum like profile pages. My experience was with the older version of the profile page and it would not resize it down to 150 in profile pages. I use the advanced version and I havent tested it yet with linking to a offsite avatars. I don't know a way around that. Are your members uploading to the forum or are they linking to a off-site picture host?