Toshiba SD-43HT disc read problem

I have a Toshiba SD-43HT home theater system. A couple months ago it become very picky about what kind of discs to play. It used to be able to play all the discs that I put in.

Now, it won’t play any DVDs that I rent from BlockBuster. The screen just keeps showing “Loading…”. However, it plays DVDs that I burn without any problem (TY and Verbatim).

First I thought maybe it just doesn’t play dirty or scratched DVDs from BlockBuster. So, I tried my newly bought Die Hard Trilogy DVDs. And it wouldn’t play any of them (“Loading…” screen again).

Anyone can help me on this problem? Thanks in advance.