Hard to say exactly what's going on, or if it's hardware or software related.
For a start I'd try cleaning the A1200's CPU slot edge connector with isopropyl
alcohol, as well as the connector on the Blizzard.
Perhaps also try another power supply on the A1200?
If you have access to surface mount soldering equipment, you could rework most
of the components on the board. Also check for dry solder joints on the
Blizzard's A1200 edge connector socket.
The flash memory on the Blizzard cards have a life of about 100,000 write
cycles. Though if you have a problem when flashing it (like a power cut) that
may cause the card to not boot again as the firmware running on it is not all
there.
