CrossRoads, I think I've spotted a mistake on all he connection diagrams that we've shown so far:
If you look carefully at the TPIC6B595 shift register on the bottom of the diagram (the one which drives 8 cathode columns) and at the connections to its pins 13 and 12 (SRCK and RCK), you'll see that according to the connection diagram the SRCK connects to the next shift register's RCK and the RCK connects to the next shift register's SRCK. It think that's messed up and should be the other way around. I think that all shift registers should have their SRCK pins connected together and their RCK pins connected together, including the shift register which drives the anode planes. In other words, the Arduino's D13 (SCK) should be connected to all shift registers' SRCK and the Arduino's D10 (SS) should be connected to all shift registers' RCK. Am I right?
Another question that came to my mind: looking at the TPIC6B595's data sheet, I se that its pin 2 is marked VCC. In our diagram pin 2 is not connected to the 5V rail. Is that OK?
Thanks,
Andras