Can someone explain why my burns are doing this? Pictures included

Recently, I have been getting some weird problems on my DVD+R's. It will encode through Shrink just fine, burn fine (always on 2X or 4X), but absolutely will NOT play on any of my 4 DVD-ROM PC drives. It just sits there and reads, like it cant really find the movie, just whirring away. They will play in my DVD players, although on my Sony it will sometimes give me a "dirty disc" message when I put it in. After that, I eject it, and they play fine (this usually only happens IMMEDIATELY after I burn one and put it in). I am using DVD Shrink, and Nero 6.6 Ultra Edition (like I have for a year now), along with MAXELL 8X DVD+R's (though this same thing has happened with other media).

Here are some pictures of the bottom of the discs. You will notice that the inner part of the DVD, on the writeable surface, there is a noticeable gap (the dark area in the photos). It seems like this is the common denominator and the problem occurs on the DVD's that have this gap right near where the hole is on the DVD.

http://img.photobucket.com/albums/v136/jblank/DSCF0007.jpg
http://img.photobucket.com/albums/v136/jblank/DSCF0006.jpg

If I can get some help, it will be appreciated. I fly a lot and like to watch my movies on my laptop, but I cant even get some of these to play on the VERY DRIVE THEY WERE BURNED ON. The firmware on my NEC-3520A burner is up to date, and I dont do anything on the PC when I encode or burn. Please help, I dont know what else to do.

EDIT-The little splotches you see on the discs are actually light reflections or a bit of dust on my camera lens. THe discs are perfectly clean and unblemished.