Well Ive got my memory card working again, but only my external drive. Here is what I did, I followed certain steps from This Thread

So what I did first was an attempt to recover the internal memory card.

(for me it shows as if the internal memory card is there asd functioning, but every time the n810 tries to access it, it reboots)

So I followed these step from above post in xterm

• "sudo gainroot"
• "umount /media/mmc2"
• "sfdisk /dev/mmcblk0"
• When prompted, type "0,,b"
• press enter enter ...
• answer "Y" to write to disk
• then "reboot"

• "sudo gainroot"
• "/dev/mmcblk0p1"

As it was reformatting, the n810 rebooted automatically before xterm got back to /home/user...
After rebooting, file manager sees the formatted disk as being ok. But same problem still, when I try to copy files to it it reboots.
I will get Back to this problem some other time.

Now for the External Memory card

I just did the same as for the internal

• "umount /media/mmc1" ----came back,... nothing to umount.. (ah ha)
• "sfdisk /dev/mmcblk1"
• "0,,b"
• "enter,enter,... Y"

after doing this the message appeared something like this,"memory card corrupt or not formatted"

• "reboot"

after it rebooted, I went in to file manager, and there it was, external memory card.

• then I clicked on ... "menu > tools > format memory card..."

and viola, memory card back in action..

as for the internal memory card problem, I,ll deal with that later