Just noticed there's an update available.
Changes made from version 2.40 to 2.50:
Addressed issue which can cause wrist heart rate to remain on a fixed value.
http://www8.garmin.com/support/download_details.jsp?id=9578
The 3.30 update seems to work just fine.
The problem lies with the newest heart rate (WHR) update, ie: 2.50. I would recommend using the previous version of the WHR. My problems started after I downloaded the newest 2.50 update. The "locked" 66bpm reading, and the heart rate dropping to the low 40s. This doesn't happen during a workout, only when I'm sitting down is when I notice the significant drop.
So we are now at two months since the last WHR update. I'm still very interested in buying this watch but Garmin's lack of support and communication is very disturbing. I know it seems to work fine for some people but there also seems to be plenty of outstanding issues especially with the heart rate monitoring. I'm certainly not expecting perfection. All I'd like to see is some effort on their part to make some improvements. Instead we get no updates and very little or no communication on the subject. Find it hard to believe that after two months they don't even have a beta of an update. It would be very disappointing if Garmin has already moved past this product to focus on something else.