Has anyone else noticed that Datasafe Blue and White DVD-Rs are not compatible with the PS2.

I have a version 4 PS2 and backed up games with these DVD-Rs.
Some worke but most didn't.
Actually the ones that didn't work, worked eventually.
The PS2 take an age to read these ones, but eventually it loads.
Thwen every time it needs to load a level after that you can go and have a coffe and when you come back its still loading for another 10 mins with the disk spinning really noisily.

I then tried the same games with Bulkpaq purple and they worked perfectly.
Anyone else seen this, or is it just me.