Problems when coping files from OS X to OS 9


I'm having some problems sometimes when I try to copy MP3s from my iBook (Dual USB, 10.0.4) to another iBook (BlueBerry, 9.0.4). It says sorry etc error -37. I believe -37.

It seems that you can't copy MP3s while iTunes is opened. So I closed iTunes copied some MP3s over. And I selected maybe 6 more and dragged them to the file server it only copied two of them. So I grabbed one that it should of copied but didn't and gave me the dang error (even though iTunes wasn't opened) so I put it to sleep woke it up and tired again error again.

So then I tired to copy 2 MP3s in a different folder one copied fine the other (the one I really wanted) gave me the error even though I didn't try to copy it before.