80% of songs on one particular album skip on iPod touch, iTunes

I purchased an album on iTunes last November, and at first it played fine. I have listened to it in awhile, and loaded it back up on my iPod touch a week ago. Now several songs skip, and it skips in iTunes as well. Oddly enough, it's the only album that does this; no other iTunes purchased album does it, nor does any ripped CD (mp3 format for those).

I tried to restore from the earliest time machine backup that I have (early June) but that doesn't help things. I'm thinking the album got corrupt sometime before June, and therefore even TM won't help me out here.

Any ideas? Kinda disappointing, since I bought it from iTunes, therefore have no CD to re-rip from. Unfortunately I hadn't done a disk burn of purchased music in that time period apparently. My last hope is a Super Dooper backup I've got on a separate NAS that is from Spring (to go back further that TM does). Perhaps that's okay.

The problems with backups is that the files exist on my laptop. On my TM drive, and on my NAS, mirrored across the Internet to another server at my inlaws' house. But if the file hasn't been changed, then it won't be modified; and if that version is corrupt, I'm screwed. Argh!!