How do I reliably get Instruments 4.x to symbolicate?

Question

I have a bit of a dilemma — no matter what I do, I cannot get Apple's Instruments.app to symbolicate any of the included instruments while I'm profiling on my devices (it works OK in the iOS Simulator).

I've tried just about everything I can think of, including:

• Checking that I'm actually building a dSYM
• Switching between Debug and Release build schemes
• Making sure that the signing certificate being used in my Development cert
• Adding and removing my Derived Data folder from Spotlight's Privacy list
• Clean & Build before profiling
• Removing the Derived Data folder before building and profiling

I'm not sure where to go from here — I had symbols for an hour or two earlier in the week, but I just can't get them to show up at all anymore. It would be great to figure out what the mystical incantation is to make Instruments always find my app's symbols.