No, I've never heard about the slim PS2 being picky about media. If anything, I would've thought it would be the other way around. I always thought that the bulky PS2 was picky about blank media?
The slim one does have a newer lens in there after all. And it does read DVD-RW and DVD+RW (albeit in Video mode only).
I used to have a bulky PS2, it wss a v4 I think. The damn thing died on me and I had to buy a slim one instead but that's another story for another day.
Anyway, the bulky PS2 that I had wouldn't read DVD-RW or DVD+RW at all. So getting DVD+R DL to playback was always going to be a no-no. :disagree: Swap Magic refuses to boot up games from these DVD formats anyway so it didn't really matter on the bulky PS2.
You say that you can boot up any type of disc on your bulky PS2, tell me; is your PS2 chipped? And also, which version is it?