O mymymymymy ....yes the method of cloning the OS indeed results in having a fat32 partition on it but that is only one of the partitions on the cloned card .
As far as the internal OR external goes it is smart to make sure that it is fresh to start with by formatting it on device...(failing that using the panasonic sd format tool software ....easily found on the web)...use the file manager... highlight the external card and the dropdown menu at the top should then offer the option to format....can't remem...don't think it's in fat32...I think it is ntfs...don't quote me on that one...just got up...it's 6 in the morning and I haven't finished my 1st cup of coffee yet So I'm notttt quiteeee at my shiningest brightest moment just yet

When hooked up to your pc normally with no partitioned fancy cards...Win. will see 2 very normal cards your internal and external.

Partition and "OS-ify" () your internal and when hooked up to your pc normally you will still see your internal and external....but you will only see on the internal what Win. is "able" to see (that fat32 partition I mentioned).

Boot up your internal copied OS AND hook it up to your pc and you bypass the onboard system and Windows has a hard time again with the linux partitions on the internal card but again has no prob with the normal formatted external card.

Unless you want multiple O.S.'s on multiple cards....my best suggestion is to put all your O.S's on the internal card and use whatever space left over for linux based storage (or whatever for that matter)...and use the external for windows accessible based storage (and if an (n800) alternate internal linux os (you have put on your card) or external linux pc can see the external card it is a bonus)....ALSO it is easier to pull the sd card out WHILE in use on the external and just pop 'er in your pc and tranfer files that way rather than on the n800. I never suggest pulling the internal out when you have mucked about with partitioning and multibooting and such on it...unless you clean off the ENTIRE device first....goodness knows what catastrophe and demons may issue forth

Oh yes....hmmm ...Can't remem. if I mentioned when cloning...keep it simple....just have the internal card in...not both....saves confusion and conflicts when cloning.

There we goeth...
Betty's yer Aunt and Bob's yer Uncle. Done...
unless more questions...I need to slurp some coffee at the moment.