How can I make my microSD card writable? I have a macbook pro running Snow Leopard.  I have Tuxera NTFS drivers.  

I have a microSD card, in an adapter, in the slot.  The "lock" slider is in the "unlocked" position.

'Get Info' tells me the drive is formatted to FAT16.  The permissions panel tells me that I can only read.

Disk utility tells me it's not writable.  (It does this for the volume and also for the higher level Apple SD Card Reader Media)

What do I need to do to change permissions to turn this card writable?
I had a PNY 32gb SD Card. Spent hours trying to find out how to make it re-writeable. Well the answer is simple. The slider on the left side of the card must be "up" (the read-writable position) BUT ALSO the tiny "notch" opposite the slider must be covered with a piece of tape. It's really the opposite of the old video tapes, which we had to break the tab if we did not want anything recorded over it. But I can guarantee you I've bought a lot of SD cards and have NEVER had a card that was write-protected out of the package that required me to do anything but raise the slider on the left side.