memory card troubles

[catbones]

here's my situation:
i'm using a 1 gig card in my 404. it's worked fine since i started using it. i filled all the banks with samples last night, then moved to a different room to use it with an amp. when i moved it, everything started getting weird.

it will play one sample fine, pretty much any sample on any bank. but after that one sample gets played i can't trigger anything else, not even banks a and b. it's driving me crazy. so what i did was delete a few samples, and it started making a really awesome yet terrifying noise. it was playing the samples but glitching them really hard. so anyway does anybody know what may have happened?

more importantly, i would really like to get the samples off the card. when i pull it up the samples are still there, but in SPD format. obviously i can copy those to the computer, but when i try to put it back on the 404 nothing happens. what do i do? i really need those samples.

thanks,