Page 1 of Beastie Boys Anthology on Wharfie 750s

I can`t get this disk to work properly!

I can play the videos straight through, with commentary. But, when I try to watch a video with a remix or a different angle, or indeed any of the extras, the DVD just wont let me. I go through the menu, and when I press play/enter, nothing happens. Occassionally, it freezes.
The disc works on my friends PC.

Anyone else have this problem?

Anyone one knbow how to cure it? All suggestions welcome (but please no `ditch the Wharfdale- I have heard it before, and its not that I don`t neccessarily agree, it just is not an option right now.)

Thanks for the help.

I`ve got exactly the same problem with my Lecson DVD 900. The videos play perfectly well with commentaries but I can`t get the extras to work at all. It works fine on my PC.
Sorry that this is of absolutely no help whatsoever, I just thought I`d let you know that you are not alone.