Which feature set you are using here. I find from the Feature navigator that the IP Plus image does not support this. I am only guessing that you are using some feature set that doesnt support FRF.8
I checked it myself and I see support in the enterprise and various other feature sets on 7200 platform.
You can check out for yourself and choose the right feature set from the feature navigator at http://www.cisco.com/go/fn
As I am making this suggestion only based on some assumptions, I would request you to share with everybody if this tip resolves your problem to benefit others.