I had the same problem and came across this thread. What I ended up doing was simply soldering the surface mounted nut back in place by heating both the loose nut and the part of the PCB where it had come loose and applying a generous amount of solder and then pressing it back together and holding it in place using a screwdriver until the solder cured. This seems to have worked nicely.
Care must of course be taken to not overheat the PCB or damage any surrounding components in the process.