I have an issue with the gradient of my 540...
The "gradient" indicator is accurate at all. Riding along a canal, it indicates on a variable scale between -4° and +3° with changes every 3 or 4 seconds...
I took contact with Garmin Belgium and after several mails, I was able to send it back and receive a new one...
With exactly the same issues.
I also have a 520 and a 530.
In desperation, I tested these along with the 540 at the same time and in the same place.
The first two showed no abnormal deviation, while the 540 kept bouncing on a completely flat surface.
It's definitely a problem with the 540's design.
