Thanks for the feedback. It does seem like wiring is the most likely cause, but still no luck.
I took everything apart, and put everything back together again using different locations and different wires, but I get the same result.
This display also has two sets of pins (on the top and the bottom of the display), and I've tried wiring using both.
I'm going to try soldering the pins on the display to see if it makes any difference.
More pictures:
Pin 1 starts at right.
1 - Green - Goes to ground rail
2 - Red - Goes to 5V rail
3 - White - Goes to middle pin of pot
4 - White - 36
5 - Blue - 35
6 - Green - 37
7 - Orange - 22
8 - Green - 23
9 - White - 24
10 - Black - 25
11 - Red - 26
12 - Blue - 27
13 - Orange - 28
14 - Green - 29
15 - Black - 33
16 - Red - 34
17 - White - Reset
18 - Black - goes to one leg of pot
19 - 220 ohm resistor going to 5v
20 - Black goes to other leg of pot, orange goes to ground
