Sound is choppy fr DVD(menus) but not for DVD option

[allycavs]

Hi

If i play a DVD with
File->Open Disc->Disc TAb
Click on DVD the film will play fine
However if I click on DVD(menus) instead the sound is v choppy
What is this issue

All other software has the same problem with choppy sound. But I can avoid the issue through VLC DVD option
But now I have a box set which i cant navigate through with out the menu.

Please help!!!

Alan