Tried to:
...import loops through the "Wave Converter"
...fails to import
...drag and drop directly to CF Card root folder
...SP-555 blinks 'EMPTY'

Loop Samples on CD are...
2116 kbps / 24 bit / 2 Channel (Stereo) / 44 kHz / Wave samples

Any suggestions?

Need to be 16 bit.. dunno why the wave converter didn't do it... sometimes I have found there are actually two different formats of file that are labelled '.wav'.. one lot works on everything ,the other doesnt...

Usually running them through a converter to convert them to .wav again will fix it (if you get an option choose "windows PCM" .wav type)

I use this
http://www.nch.com.au/switch/index.html

you also gotta watch the naming cause i remember having a long ass name for my samples or a symbol in the name. cause i thought it was the 16 bit thing at first till i tried hundreds of conversions, then i changed the name to something simple like "sample 01" and then it worked. loading through the wave converter is a pain in the ass. you might wanna get used to setting your 555 to sample on input, like when it hears a sound that goes above a certain level it starts sampling. then line up your samples in winamp or something then start sampling one by one, your learn that it is much quicker than going through wave converter, doesnt sound like it but it is. and you can turn on the lo-fi for each if you want. be nice if you could drag and drop but you gotta hit, load sample for each sample, gets kinda time consuming.

Thanks!