I'm not sure whether this is helpful or not, so please correct me if I am totally off base. I know that when heart rate monitors first came out, they had issues with interference... especially with other cyclists being in a close proximity to you. I still find that issue to some degree in the shop trainer class, although generally I set up the bikes a bit apart and in a diagonal pattern and it stops. Anyway, I wonder for those in you in shop trainer sessions, if this could be the same case? Are you too close to each other and that's why there are problems with the units not reading?

I'll keep following this discussion and see what those of you in trainer classes have to say about it. Although I haven't bought a Garmin (yet) I'm thinking that the 800 might become a part of my stable as well.