Solder bridges can be sometimes be invisible to the human eye so running the craft knife is a great idea. Also check the orientation of the trannies.
With a straightforward circuit like this it is probably worth making an audio probe -
http://www.diystompboxes.com/pedals/debug.html .. using this probe you can step through the circuit starting at the input and follow the signal path through and hopefully identify the faulty component (s).
Another useful hint for using an audio probe is plugging a low level sound source into the input of the effect so that you have both hands free to test the circuit (rather than doing a juggling act of silmultaneous strumming and debugging).
Good luck.