When connecting my N810 through USB to my Linux desktop, I am only able to access the internal memory card. (it appears as /dev/sda)

The external, which I can access from within the device, is not available.

Any help would be appreciated.

Thank you

Two things I have noticed on my N800. First, I cannot see or access my external memory if the N800 is running a program that is accessing a file on that card. Second, many times I just unplug and reconnect the USB cable and now both memory cards appear when viewed on my desktop.

Ok. Well I rebooted and haven't started up any apps yet. I guess something in the background could be accessing it.

In fact, with my N800, every time I first connect the USB cable to my Windows XP desktop it always only shows only the internal memory card. I always need to unplug and plug back in the cable to then view the internal memory card. Your N810 may react differently.

Try running "lsof | grep media" on the tablet, when the external card won't show up. Examine the resulting list of open files.

From my N810 I have full access to files on my Ubuntu PC. Bluetooth provided that capability. I use a bluetooth USB dongle on my desktop. I now only use N810 USB to connect to card readers and memory sticks.

I sometimes have this problem, try removing and putting back the mini-SD (physically, not in software). I think it's because of my cheap µSD/MiniSD adaptor which doesn't make good contacts, maybe it's the same for you.