Are you using the iCP in iCade mode or still the packet mode?
BTW, Flashback with iCP on my iPhone is awesome!
On that note, I think the mapping between the iCADE and the iCP are awkward based on the layout of the controls.
The iCADE button layout is as follows:
A C E G B D F H
We can look at the iCADE as having two banks, A B C D and E F G H. With that in mind, I came up with the following mapping, which keeps the orientation of the buttons closer to their equivalents on the iCP and also grouped together. A/C and B/D buttons are side by side, so I mapped the SELECT/START and L/R shoulders respectively. For the E F G H group, they are in a square:
E G F H
We can think of the iCP as the same, just slightly rotated into a diamond:
Y B A X
This brings us to the final mapping of:
A = SELECT C = START B = L-SHOULDER D = R-SHOULDER E = Y G = B H = X F = A