HTML in posts after board conversion

Hi everyone.  I am sad.

I had a pretty active board running on Discus Pro.  I wanted to switch to PunBB.  So, I spent a long time using a script to convert from Discus Pro to phpBB2 and then from phpBB2 to PunBB 1.2.  I think upgraded to PunBB 1.3.  Everything looks great and I was happy at first.  Then, I discovered that all of my converted posts actually had HTML code in them from Discus Pro.  Now the posts are basically unreadable since there's so much HTML code peppered through them.  I've been changing a few of them by hand, but there are more than 8000 posts and that would take forever to do by hand.

Is there any way to get rid of all this HTML code either through an extension, mod, or some database method? 

Here's my site if you want to check it out.  I'll link an example of the problem:  http://www.atomorrow.net/forum/viewtopic.php?id=182

Thanks for any and all help!

Ryan