Bike Forums - Trainerroad Cycle Computer Relay question

So I'm using trainerroad, using the virtual power function. Which, I know isn't very accurate. I'll gladly PM my address to anyone willing to donate a power meter, until then, I'll continue the "My bike didn't cost as much as your power meter" approach of VirtualPower.

TrainerRoad also has this nifty feature of relaying data using ANT+ to a cycle computer. Which, in my case, is an old iPhone 4 in a Wahoo Bike Case with built in ANT+. Not that I need to use it, at all really, but I figured 'why not'. And it gives me some more meaningless data to look at.

One odd thing though, is the power numbers. My "computer" recognizes trainnerroad as a power meter. Which is how it's supposed to work. And, in theory, the sensors feed trainer-road, it crunches numbers, and fires back speed, cadence, and power. What's odd is, the power numbers on the WahooFitness app (the app I happen to be using, since it supports indoor cycling) shows a significantly lower power number than TrainerRoad. For example, TrainerRoad might estimate I'm doing 100 watts, while WahooFitness is showing 20 watts. How does that make sense? They are pulling data from the same source, and TrainerRoad is supposed to be feeding the data directly to the computer!

Is something configured wrong? Anyone have a suggestion? It's sort of bizarre. For the record, either I'm as frail as the old ladies at the nursing home (possible); or WahooFitness is severely underestimating my power output.