Cory,
sounds like classic gummy lubrication on the latches for those pushbuttons. Some spray lubricant usually does the trick, but it might only be temporary. The real solution is to get some more permanent lubrication in place, e.g. light machine oil. There's a flat spring over the front of each latching switch and I try to get some oil on each of those springs, then exercise the switch a bunch of times to get things loosened up and work the oil in to the mechanism.
For my instruments I have been spraying DeoxIT into the back end of the push switch and exercising the switches. If the switch is still sticky I hit the front with some WD-40, on the basis that it will penetrate the gummed up works better. That's been working so far, but I suspect that the WD-40 will evaporate and what remains may get gummy again. So long as that takes more than a few years, though, I'm happy. If they gum up more quickly than that I will try using light machine oil instead.
-- Jeff Dutky
