I am a little confused now. After shutting down the G1, removing and re-inserting the micro SD card and starting the G1 again, the folder /sdcard is visible now.

Download works fine now ...

Thanks for your support.

Do you have a sdcard ?

Yes, of course. A 2GB micro-SD card. My problem is obviously how to address the SD card ...

I have got a similar problem.

When I try to create a folder "sdcard" (of course without quotes) with AndFTP in the root directory on my local device an error message pops up:
Cannot create folder: sdcard

The contents of the root directory starts with:
/cache
/data
/device
...

Any proposals?