I have not touched a Memorex CD-RW since I bought a 10 pack of 80 minute 4x discs:
That was the worst of the lot. The other's didn't fare much better. 8 out of 10 died within 2 months. Several were dead right out of the box.
I have read of other's problems with the 10x Memorex CD-RW's. I don't often 'throw good money after bad" so I just avoid Memorx for CD-RW's.
As far as I know, Memorex are the only one's shipping a 24x CD-RW that is 80 minutes long. If they were made by anyone other than InfoDisc (even CMC) I'd try some.
I learned from my mistake (& other's). I just use Verbatim CD-RW's now.
I've never had a bad disc yet (and I own around 30 Verbatim's).