I have tried everything I could think of. Also I red most of the relevant topics here. Could someone please tell me how they do it. I have MacBook Pro OS X 10.6 and PC laptop winXP to choose from the computers. I am using Topfield card reader if that matters.
I am pretty much ready to throw this thing out of window.

hi
i got a win xp sp2.
make sure that:
1)the sp303 can read only .wav/.aiff audio files.
1.5)i don't remember if you have to write WAV or AIFF at the end of the file, but i believe no (ancient thought )
2)have you put the smartmedia card in the right direction (the gold face has to stay "down") inside the 303?

ahhaha i just replied to the other (double) post... but anyway good points too

additional:
the files need to be names SMPL0001.WAV (or AIFF) - all caps, 8 digit file names

don't worry man !
anyway you're right to point that, i had fogotten that the SMPL0001 thing is true! you cannot rename the samples other way...

No, no!
I do everything it says in the manual.
I make my sample 44khz (I have tried stereo and mono) about 1sec (1000ms) long. Naming SMPL000x.WAV. I use OS X Audacity. Transfer files to PC.
I format the SM card in SP303.
I put files on the card.
Start with card = no wav's....and the card needs to be formatted.
Only what I have not tried is to make the file with PC.

i'm afraid that your card is not working...
is it 3.3volts? also if it is, sometimes (don't know why and how) it happens that those damn smartmedia don't work...

My card is OK, I think. When I mount it it will show 3 files. And I was able reload the firmware.
By now I tried PC to re-export the files. No good.
The only thing I have not been able to test is the card reader. I just have one.
Could you tell me how YOU make the samples and transfer these. I could then follow step by step and see if I have missed something.

i made this as written on the manual, exactly like this and, i suppose, exactly as you done.
are you sure it isn't the card itself?
maybe as you said it's the card reader.
in that case try to buy another, they're very cheap.

I was able to get the files in by formatting the card first to FAT on mac. Formatting the card in SP303. Load .aiff's and start the Boss with the card in. I hope it will continue to work this way.

cool

Cool enough - but how to load samples off the card to the bins C/D and not to have to do this again every time I restart SP. If I remove .aiff's off the card SP will not see recorded samples any more. How do you do it?

can you explain what you mean?

i remember i got similar problems with the sp505...
it cannot read samples with the 128smartmedia it cmoes with; if i format that smartmedia on the sp303 the 505 reads samples...
is this that makes me say that maybe is your smartmedia that is not well...

what do you mean - isn't the problem solved by formatting the card once? if you put your new aiff files on there, does the 303 not recognise them all over again?