I have the same problem, posted a couple times about it on the forums, and never heard a response. I don't think this feature is used much, since no one seems to be able to help.
I was having the same issue, but just figured it out! The phone identifier codes is the FULL code that 41411 sent to you...INCLUDING the "TM#"
For example...follow the instructions to text 41411. You'll get a reply that says, "Hello! Link your account with device identifier TM#1234567 and password a2Bc."
On the geocaching page, Trimble's Geocache Linking in the box asking for your phone identifier use the entire "TM#1234567" not just "1234567". Make sense? And the password is case sensitive. Been playing with this for weeks now and JUST got it to work. Hope this helps!
