Posted about this in this thread (https://www.obitalk.com/forum/index.php?topic=19199.0), but figured I'd mention it here for visibility's sake.
Basically, X_CheckVoiceMailWithCallKey doesn't work on the 2182. I have four of them all running firmware 6.2.3 (Build 5330.1311), and holding the key down only shows a configuration menu as opposed to dialling the number defined in X_CheckVoiceMailNumber.
FWIW, this problem doesn't exist on my lone 1062 (firmware 5.1.11 (Build: 5312EX.1311)).