Mounting a SD card as RW still give RO filesystem

[david-8uUts6sDVDvs2Lz0fTdYFQ at public.gmane.org (David Kramer)]

Dan Ritter wrote:
> On Mon, Nov 02, 2009 at 11:58:50AM -0500, David Kramer wrote:
>> I'm trying to copy files from my laptop onto the MicroSD card for my
>> cellphone using a card reader.  This has worked before, but now no
>> matter what I do, it says it's a read only filesystem.
>>
>>
>> So it's mounted rw, and I can't even write to it as root.
> 
> Does it have a write-protect switch on it?

No, this is a MicroSD card.  The ones about the size of your fingernail.

And the phone can write to it.