I've never experienced this problem, but I have seen mention of it from others here on the forum. The general consensus is that sunlight (or, perhaps, some other source of infrared light) is triggering the infrared sensor on the front left side of the GPSR, and the GPSR thinks it is getting a command from the handheld remote.
The simplest and most trouble-free way of testing this theory is to put a little bit of masking tape or electrical tape over the infrared sensor, and see if the beeps stop. As Ian mentioned, the most recent software update for this GPSR gives you the ability to turn off the infrared sensor if you don't need it - meaning, if you don't use the remote.
Don't bother phoning about it until you have tried out one of those solutions.
Michael