Yup - happens to me once in a while. Usually with a complicated wiring scheme, but occasionally with the simple stuff. Couldn't figure out why the neck tone was acting like a volume pot last week. I had soldered the cap on wrong . . . DOH!!!!!
Maybe its not me.... Now that I play the guitar (a nice LP clone) the tone controls are not acting right at all and the neck pickup is very muddy sounding. The tone controls completely cut off the volume when turned to 0.... what gives????