EXS 24 Logic Sampler Users Group

I just started working with EXS a few weeks ago, and I've run into a 
big problem: all of my sample instruments, whether converted from my 
Akai S-1000 disks or from other sources, are sharp by about 1/4 tone. 
I'm using a Korg Oasys card, and the manual says that this can occur 
with incorrect word clock settings. As far as I can tell, though, my 
settings in Logic and in the Oasys preferences are correct. Any ideas?