Problems playing DVDs

[brener]

I recently bought a bunch of ayu DVDs from Yahoo Auctions Japan, turns out I'm having problems with the encore segment, the player just won't read them, the screen turns black, I hear the disc spinning but then it just goes back to the menu. I tried a lot of things like pressing forward until the encore, but then it stopped. Also, I tried selecting the encore section on the menu but it won't play anyway.

This is happening with her older DVDs (DOME Tour 2001, ARENA Tour 2002, Stadium Tour 2002 and CDL 2002-2003..), which is strange because CDL 2001-2002 played correctly, Dome Tour wouldn't play for anything, but then I played CDL 01-02 again and put the Dome Tour again and all went well (???), except for encore.

I believe this is a problem with my player (which I region-unlocked - and may be pretty dusty in the inside since its more than 10 years from the last time it was used) or the discs being too old, did anyone have this problem too?

If you guys have any advice I'd be grateful, I'm seriously thinking about buying a japanese dvd player so maybe this won't happen anymore..