WHY are My Forums Signature Links NO FOLLOW

I recently installed a firefox SEO plug in, and found out that my forums links are NO FOLLOW ! This sucks! No wonder why many of my regular posters have abandoned my forum to post on forums that ARE DO FOLLOW!
Can this be changed ?

Hello,

What do you mean? Could you explain more?

Yes, all my forum signature links are NO FOLLOW, meaning the forum software is telling Google NOT to follow the links. This means my posters do not get any link juice for posting on my forum! This is an old school attempt to preserve page rank and stop spam, but posters of today are smart. They will see the Forums NO FOLLOW links, and go post somewhere else on a forum that is DO FOLLOW, and will give them some link juice for posting there. This is a serious problem! Forum Owners need to have the ability to change this. VBulletin and Simple Machines have options to set either Do or No Follow, as do many other PHP Forums.

Could you post me a link to where this is or a screenshot?