When ever i'm in game my push to talk will not work in the game. This has happened to about 20 of my clan members aswell. Only way to make it work is by using voice detection.
Glad you found your solution. Protip: Edit your TS3 shortcut so it always runs in admin mode when you start it up.
Yep, you should always run TS3 as admin. If not, the program you have up front (such as Planetside 2) takes priority. And, the shortcuts won't work.