Rob,
I like the theory, you could well be right about the 'wide blunt rudder' business.
I must admit my technique when tacking is to just heave the stick over as far as it will go in an effort to turn the boat through the wind as fast as possible. Perhaps a litttle more finesse is called for and I ought to ease the helm over, which may alleviate the 'stalled rudder' syndrome? I'll try that next time.
In the meanwhile I'm changing the Rx to 40Mhz as there's a couple of kids who 'drive' (the word being used in its WIDEST possible sense...) some buggies in the park where I sail, and they hadn't a clue what I was talking about when I asked them what frequency they were on. As it turned out one of their sets was on blue, and the Volvo is on green, a tad too close for my liking, thus the change to 40 Mhz.