Why does DeCSS sometimes "break" menus and photo galleries?

[dbminter]

I've noticed on a handful of DVD's that the simple process of DeCSS'ing a DVD can sometimes "break" the navigation of menus and photo galleries. What happens is when the content is played, instead of delaying a few seconds before showing the next gallery or waiting for navigation input on a menu, each subsequent photo/menu airs one after the other with no pause whatsoever. So, my question is why is this? It should be just a simple process of removing CSS, but, I've notice this happen on 3 DVD's I've read to image files. It doesn't matter what program I use, the results are always the same. So, it's a result of the DeCSS process.