It is called group by materials.rb. You're on the right track. Take a look at Didiers side.

ah you are a life saver thank you very much it works great now. i dont understand how the bracket got deleted though. i used the same zip file that i use on my other computer and that one works fine too.

I'd like to see a smaller sample model that causes this problem. You can either PM me or contact me through http://www.smustard.com and I'd be happy to look at this. Thanks,