"Was mounted to drywall"
That's a big no-no, but I've seen some slammer jobs like that myself.
And yeah, there will usually be darkened spots on the drywall around the top vents in this case.
When you say "calls are being interuppted", what exactly do you mean?
Anyway, if you want to upgrade the ole R.3 to a R.6 and pull the translations off of the B/U card (if the installer did a B/U) to reload to the new R.6.
Flash the R.3 to a R.6, pull down a B/U then restore it to your new R.6.
Good Luck!
