I too had this problem with my sandisk 6gb card, and inadvertently formatted it via windows xp to give me 1.6gb.

The sollution / workaround I found was to reformat the card (using the supplied sandisk dongle and sd adapter using sdformatter v2.0 from the panasonic website.

SD Memory Card Formatting Software | SD/SDHC Memory Card | Digital AV | Product Support | Support | Panasonic Global

Once I had restored the card to 5.6gb, I was able to put the card back into my BB and it showed the correct capacity.

*NOTE: when you put the sd card back in the BB if it say that the media card needs formatting or any other error message, ignore it, go to settings - advanced - media card. Turn off media card support, back on again and then save the configuration.

If you try to access the removable drive through windows i.e as a removable drive it shows it as needing formatting so you will always need to use the sandisk dongle and adapter.

I have found that each time I remove the card to add extra files you need to repeat the above step *.

I have a 4gb card as well and none of these issues apply.

CONCUSION: All file transfers to a 6gb card need to be done through the sandisk dongle and adapter!!!

Hope this helps others.

Riverdude