Built in therms are notorious for being off a lot in most cases. A shoulder has a bigger bone in it than a butt does, so there's that consideration as well. I, personally, after being burned a couple of times by stalls and stubborn chunks of pig now always allow 2 hours per pound. I can almost guarantee at one hour per # will be insufficient time. Yes, never get the probe wet, clean with a sponge or alcohol wipe. 145 IT is pretty low....I doubt near the bone will be done enough for most people, but....that's just me. Now, a pork loin I could see at 145 IT. I take all butts and shoulders to 205, then rest for an hour (best case secnario) and pull them. I recently did a shoulder to 190 and had to slice it....it was tasty and cut very nicely but could have used some more time in the smoker. I would suggest a quick trip to Target or Wal-Mart for a inexpensive digital probe therm, then do the boiling water test for accuracy (212 degrees) and use that and the other as well, for grins or for chamber temp monitoring. HTH, Willie