I have no idea how to help you as I can't figure out what you are trying to do. Are you:

1) Trying to copy files from one place on the N900 to another.
2) Trying to copy files from a computer to the N900
or
3) Trying to copy files from your old phone to the N900

A little more specific question would be more likely to get you the help you need. Oh yeah, a better subject field with some information about what kind of help you need would also get faster results.

I hope you get it straightened out.

Fred