I have been using one of these units for a year or so and am very happy with it. However, it is currently running firmware v3.3.6 while the latest version is v5.2.12. Should I follow the principle of "If it ain't broke, don't fix it" or are there features or improvements in the intervening upgrades that would make it worthwhile upgrading this firmware?
Second question: when I am on a call, if someone calls my number, they do NOT get a busy tone, they just get silence. I, on the other hand, get a call waiting tone in my phone - but how can I put the current call on hold and switch to the second call? I have tried the recall button but nothing happens. I have looked in the manual (well, I've tried wading through the 271 pages of it!) but can't find anything to help.
Any ideas, fellow geeks?