Problems using Garmin 310XT with PM4

[jasperm]

Hi - I've been setting up multi-step programs on my 310XT (can download from Garmin Connect or Garmin Training Center) to use on my Concept 2 Model D with PM4. Unfortunately, steps I set up randomly get truncated - that is, the watch will skip to the next step before a step is done - but it happens differently each time. I'm thinking it's some strange interaction between the Forerunner and the PM4. Has anyone else run into this?

Thanks,
Michael