While I was out at the lake testing a new diffuser I noticed that there was something odd going on with the light. At first I blamed the diffuser, but then I realized that my MT-24EX was firing at almost full power, even though I was only shooting around 3x at ISO 100 and F11. Later on that evening I realized what was going on while taking some test images at my kitchen table -the "B" flash head was only firing intermittently.
That's two hardware failures in as many weeks -bummer.
I guess if the gear is going to fail I'd rather it happen now then early next spring. Canon has already given me a repair estimate on my MPE-65mm (about 200 USD) and I sent the MT-24EX to the service center in New Jersey this morning. With any luck I'll have all my toys back in about two weeks. Until then I'm going to explore using a standard camera flash on a bracket.