Reply by ChuckH

Thanks for all the tips! I’m going to try the glue-then-screw strategy next time I have a chance. In this case I ad the bright idea that I would assemble the frame, use a 3 wing cutter to do slots for the side panels, then disassemble and insert the frames. Bad idea – the frame parts are so small, I kept hitting the screws with the cutter. At least it was a cheapo HF bit, but it still stings to do something so dumb :)