I ended up calling a buddy with a bit more experience. He put a few 2" screws in there (and shimmed under the wall). It still squeaked. At this point, it looks like I'll replace the crappy old 1/2" plywood with some new 3/4" plywood.
Thanks all for all the help...
edee em ( snipped-for-privacy@home.com) wrote: : I had a few spots like that and I found that shimming under the sole plate : for that very wall helped, Put glue on your shim as you won't be able to : nail it down. On one area I blew some expandable foam into the gap under : the sole plate (yes it was out that much). Also keep in mind that it might : be connected to truss lift (the roof raises pulling interior walls up with : it).
: Good luck
: > Any ideas on what to look for, what to try etc.? : >
: > Any help appreciated : >
-- Geoff