I think you're right about TDMA on Fastlane from what I remember. It's why I got the lifetime version. The latest version (2.256) is really cool as it shows you the recently active talkgroups and the radios as well.its not showing any talk groups being decoded. I think i have 2 problems, I think only the FASTLANE app has the TDMA decoder and I think the RTL dongle i am using is out of calibration. I was going to play with it more today.
If you can, I would highly recommend picking up this dongle as well. I have a few and never have to worry about drift with them.