More Garmin problems

Good Morning

So I am having some repeat problems with my Garmin 310xt.   They seem to show up when I
attempt to upload to the training log.  For instance this morning I did just over 24 miles on the trainer.  I plugged in my stick and it automatically loaded to the Garmin site. 

Then I went to the training log and the first thing was the message came up that my communicator was out of date.  I closed out explorer logged back in and then it was ok.  I selected the device and uploaded and it said it was ok.  When it
showed up it was 17.8 miles, not 24.  This has happened at least 6 times over the past few months.

I do notice that I am loosing the heart rate at times.  Still the lap mileage is there, but the summary screen shows less.  I don’t know why I am loosing heart rate.  I have a new strap, new battery and I was shirt less, so no static.  I do not wear headphone so no wires crossing the transmitter.

The next item is I tried to upgrade the firmware to version 3.7, I am still at 3.2  So I get that resting heart rate message stuck on my screen.  It says it is uploaded to the ANT+ device but does not load to the unit.  Am I missing a step.

So any suggestions?

Joe