I don't buy the line that it's a "common problem". It's just a BS line that they're using to make you go away. Ford would not manufacture something that is problematic especially if it comes down to safety. Do you know how many vehicles on the road have TPMS these days? It's so common, that it's not possible for it to be a "problem".
Take it to another dealership, because they're obviously not getting it right.