Serious problem: bought "Bad" DVD+R media, do I return it?

I just bought a 4x DVD+R burner so I’m new to everything, but I’ve already run into a problem.

First DVD+Rs I bought were a 5 pack of Memorex 4x for ~$11. They burnt fine and are readable in my DVD-ROM drive, but a tad on the pricey side at $2+ each.

Second pack was a 10pk of CompUSA 2.4x for $14.99. I’ve only burnt one and it reads fine in the DVD+R drive but the DVD-ROM doesn’t read it, just sits there and spins forever.

What can I do? Back of the label on the package says:
“Compusa warrants that this product is free from any defects in materials or workmanship for ninety days. If such a defect is discovered within this warranty’s limitations, Compusa agrees at its sole discretion, to repair or replace with the same item or one of equal value, free of charge to the original consumer purchaser. Return to the store where purchased. (etc)”

Sounds fine and dandy, but it still worries me. Has anyone else experienced this problem? Should I just suck it up and never buy CompUSA media again, or should I at least go to the store and see what they say? What if they say since I opened it and used one I can’t return them? I know there’s a 90 day warranty (bought them 2 days ago), but it’s at their discretion, they could easily say user error or drive error and not their problem.

What would you guys do in my shoes?

I went ahead and burnt a second DVD+R and the problem’s the same, not readable in the DVD-ROM. I also got a verify error (got that last time, but didn’t mention it), but like last time it seems everything was burnt to the disc, I can copy files from it and the .sfv verifies fine, it’s just not readable in the DVD-ROM.

I am burning the CompUSA media at the suggested 2.4x speed but that doesn’t seem to help.

Obviously my primary concern is whatever I burn to these CompUSA DVD+Rs will be completely unreadable in any drive within a few weeks/months. What good is a unreadable backup?