I just lost the coin toss and the screen grab is after the computer has finished out his turn by playing 4 Quantum Towers. The amount of mana banked should be
(4 x 3) for playing the QTs
+ (4 x 3) from the QTs by finishing the turn
+ 1 from base element
---------
25 total
However, adding up what actually happened, there are 43 banked. I don't know where the other 18 came from, but they're very annoying! It's easiest to track on the first turn, but extra mana appears for all subsequent quantum towers the computer plays. This happens to me on any computer controlled top50 deck with quantum towers.