Interesting behaviour I just observed with the ledger and staking. Seems that the way it sends funds away is last in first out.

So my observations were that the last transactions in to each of the staking addresses was for the rewards, but prior to that I had sent some funds away from 3 of the staking addresses, 120 Zen out of 126. This resulted in 6 Zen being moved to a new address on the ledger.

Then I moved back into the 3 staking addresses exactly 42 Zen each. This then gave me a balance of my total stake plus 6 Zen.

Now once the rewards came in, I tried to send them plus the 6 Zen to an address in my Arizen wallet, and what I saw was that it sent the rewards but then took the 6 Zen from the last transaction of 42 Zen sent to the staking address instead of the 6 sitting by itself and moved the 36 Zen change to a new address on the ledger. I previously thought it used the smallest notes first.

Further testing showed that I needed to send away the other 42 zen notes up to the point where the 6 zen was remaining then include that additional 5.9999 to clear the last in, first out notes.
I first cleared the 36.0001 residual from the tx last night (
Then I tried to just sent the 6 (5.9998 + 0.0001 fee away and got (
And to finally clear the back log I had to