Thanks for the quick response! Since the only things on the 323 are media files, I selected "root" and hit refresh. The PS3 now sees the media folders. However, when I open some (but not all) of the music and photo files, I get DLNA 2101 and 2103 errors and a statement that there is nothing in those files (when there clearly is). Also, when opening photo files, I sometimes get thumbnails and sometimes I don't. Note that I only open music folders when under the PS3's music tab, and photo files under the photo tab.
It seems like I am at least on the right track here, but the persistent errors make it tough to enjoy the 323 through the PS3. Any other tips would be greatly appreciated!