It seems like copying a file onto the SD card ought to be easy, but for the life of me I can't figure out how to do it. I have an (International) Motorola Xoom Wifi running stock Moto Android 3.2.

If I insert an SD card with content on it, I can see the contents of the card show up in the tablet's Gallery app. I can also go into the built-in Files app and browse the contents of the SD card. Using the Files app I can select files and copy them from the SD card to the internal storage.

However when I browse the tablet's internal storage with the Files app and select and `Copy` a file, if I then navigate to the SD card the `Paste Here` option is grayed out.

Using File Manager HD, I can't even find the SD card. It looks (from the Files app) like the SD card is at `/mnt/external1/` but I can't see any way to get there. Is there something I'm missing in File Manager HD to find the SD card, or is there a deficiency in File Manager HD that another file manager could solve?

Also strangely I can delete files from the SD card using the gallery app, but not using the Files file manager app!