I have been using the HRM 600 for about one month now.
I use it daily for a minimum about one and a half hours per day.
I have just noticed that I have some skin irritation and small scabs forming in the middle of my chest under where the heart rate module rests.
I have used Garmin HRM straps for over 10 years with various versions of the HRM, HRM run, HRM tri, HRM pro HRM swim etc.
Never before have I had any skin issues.
Has anyone else noticed this?