All I can even begin to guess at is that with the budget being so low, and the popularity of the title upon its video release, it's probably a pay dispute. That helps me sleep better at night thinking it has to do with money so I can lay it to rest.
I bought a 2nd copy through Shout! Factory's website to get the uncut commentary, having never even seen the sequel. That being said, SPM part Deux was so horrible, I seriously doubt I will ever even listen to the commentary. The movie made me want to gouge my eyes out with a hot poker. I'd rather have hooks stuck through my manboobs and hung from jungle trees by natives than sit through it again.
I think most people could agree, the movie hits a low point in one particular scene involving music... I don't want to give it away, but I was ready to take the disc out and break it.