why is RW-mounted SD card treated as mounted RO?

[Robert P. J. Day]

  perhaps a simple solution to this, but i tossed an SD card into my
ubuntu 10.04 laptop, whereupon:

$ mount
... snip ...
/dev/sdb1 on /media/6458-0D98 type vfat
(rw,nosuid,nodev,uhelper=udisks,uid=1000,gid=1000,shortname=mixed,dmask=0077,utf8=1,flush)
$

  that normally suggests that the card is mounted read/write, but if i
"cd" onto the card and attempt to make any changes, i get:

$ touch fred
touch: cannot touch `fred': Read-only file system
$

  am i overlooking something obvious?  the SD card is unlocked, the
mount comment certainly suggests that the filesystem is writable, but
any attempt to modify the card contents fails (sudo makes no
difference, and that would generate a "permission denied" error,
anyway).

 thoughts?

rday


-- 

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Robert P. J. Day                               Waterloo, Ontario, CANADA

            Linux Consulting, Training and Kernel Pedantry.

Web page:                                          http://crashcourse.ca
Twitter:                                       http://twitter.com/rpjday
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