So for a little while i had to drop my DP back to SDR.
once i had cleared enough space (74% used) i was in a position to re-enable DDR.
I had 8 x 2Tb in SDR - all green and happy
check the DDR box & then “ok”
little popup from the system tray says it enabling DDR the pie chart capacity drops by 2tb - all exactly as i expect, and the pie chart starts to flash green and yellow while its doing it stuff. Perfectly normal.
i went into “advanced” to see how long it would estimate this re-layout and enabling of DDR would take.
however the drive indicators there were not flashing yellow/green. there were 7 solid green and one solid red (matching the front of the unit!) - and it did not have an estimate of time remaining - instead it just said data at risk and that i had to add a larger drive.
for the moment im leaving it as it is and seeing if it is doing the relayout and if it will come to its senses once that is done,but i was surprised that the “advanced” tab shows something very different to the pie chart (still flashing as if it were doing the DDR relayout)
I’ve also opened a support case and sent in a log asking if it is in fact busy converting or not, perhaps this is just a cosmetic/flawed logic type of thing.
Either that or when its 74% full it thinks it has enough space to start DDR, but then once it tries it , it then thinks it doesnt have enough?!
not really expecting much feedback since aside from wait and see, there isnt much to do, just thought i would keep you guys informed 
http://picasaweb.google.com/lh/photo/ysXIDtnwnFOeLuVycu6OAA?feat=directlink