Okay I got a cateye double wirless speed and cadence computer. love it. I also have a sports instrument HR monitor. It seems my HRM is being affected by the Cateye even though the cateye is has a coded transmission. I really just need a good HRM that won't mix signals. I'm also a mac guy so downloading sessions doesn't really matter, unless you people know of a good HRM that's Mac compatable. That would be great. Have any suggestions?