The Distinction for the LS Pro Duo's is v1 or v3.
The 1TB and 2TB use the same firmware (I've used both).
However since you've replaced drives, the updates may not work as expected (I don't think Buffalo will support it). Just an fyi as you may want to consider the risk before venturing for that upgrade, given your situation ;)
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@Charles,
Awesome that it worked out. :) Where I tend to get worried is when using drives such as 'WD Green' where they might try and park during the update. Delayed write-failures during a firmware update would bring you to the FAQ topcis on this forum.
Just a curiousity question, what drive makes/models did you use ?
And thanks for posting your results, might help others facing similar situations.
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