Framing error if I disable transmitter after shift register is empty?

[Ioannis]

I don't have carpet, and that's the extent of my ESD protections.

Well the carpet is one thing. Even if you just walked the room and returned back to you chair (even worse if it has suspension), then you may well have charged enough to destroy the chips.

You have to remember to ground yourself just before you touch components or even better have a wrist band to permantly ground your body (through a high value resistor of course).

ESD can destroy just a tiny part of the chip, enough to drive you crazy!

Ioannis