I have 2 problems on my ASuS Allin one computer:
The volume is rarely loud enough to hearproperly especially with DVDs and it suddenly stops mid session at any time withou reason and I have to force closure by turning the computer off.
there are several volume options. first is windows volume, second is the dvd playing software. third is if you are using a set of external speakers. if you are using internal speakers then they just might not be very loud.
sounds like the software is locking up... you can try a different one.
without giving us any more information there isnt much we can tell you except generic ideas.