It doesn't look like anybody answered this one. I found the answer in another thread (thanks Netherworks for posting the answer there), actually, because I was having the EXACT same problem.

The extension for the pose files is .pz2. Poser 8 does not like it when that extension is instead .PZ2. If you manually rename the file to be .pz2 instead, it should work. I just did this with the lovely Circe character that I could not get the morphs to load on and the morphs load just fine for me now. Hopefully the Smith Micro people are aware of this (I am going to report it there just in case it hasn't been reported already).

This is the thread, by the way, that contained the fix: www.renderosity.com/mod/forumpro/showthread.php