Hacking a camera flash

I was thinking about making a slave flash for my camera, and came across this post, which talks about re-purposing a disposable camera for just this purpose. Sounds good to me! I pulled out an old camera and extracted the flash unit, but unfortunately part of the circuit went with the camera body, and I had to build a little clock to control the inverter. The idea mostly works (I got the unit to flash!), however the transistor overheated and melted part of my board. That needs to be stabilized before the slave flash trigger bit is added. A messy schematic is here.
Update: A prettier schematic is here.