nah yonder's sets are rarely even that long
im going to bet that this card is fine- it is a sandisk ultraII which I know people have used in the past. I also know that it formatted fine inside the player and took the new firmware off the card just fine.
i dont have time to test otherwise.
I just recorded Yonder's Boston show using a Sandisk UltraII (4GB), I ran at 24/48 from my S/PDIF input, and it went great, no problems at all.
as far as set lengths, they played an hour first set, and an hour and a half second set. if they play an hour & a half, you'll be cutting it real close with a 1 gig card in there. up to you whether or not you want to risk it.