Oops. The photo interrupter's collector wire wasn't connected to INT0 on the ATTiny. That has been fixed now. Also, the board is now 1 mm wider so there is enough clearing from the segment A wirepad to the edge of the board.
And the VCC and GND traces are now 24 mils and all other traces are 12 mils wide. Refer to the first layout if you can't remember what the various wirepads are for.