Why Doesn’t My Blu-ray Drive Play This Disc?

I watch Blu-Ray movies on my Dell Studio 17 laptop using Dell MediaDirect. I bought TRANSFORMERS on Blu-Ray (the two-disc edition) and I can play the fist disc without any problems. However, while trying to play the second disc, I get the error message “Unable to detect a DVD or DVD device on your computer”.
I think it is unlikely that my drive has a problem because I can play other Blu-Ray movies on it.
Kindly assist!

Screen Saver Doesn’t Work On A Dell Laptop With Vista ?

I have a new Dell laptop with Vista loaded into it and for some reason the screen saver doesn’t work… If I check it on the set up page it’s fine and if I let it set while it boots up with out touching anything it’ll work the first time… But after that first time it doesn’t work… I’ve tried different ones and changed settings but nothing works…
Any ideas…???
Vista Home Premium
17 inch monitor
2gig dual core processor
250 gig hard drive
3 gigs ram