I agree. Have you checked to see if you have the latest firmware installed on your console? I checked my high low feature on my console and it does some weird things too, but my console is so old, and no more firmware updates are being issued for old consoles, I am not surprised with my results. If you have a fairly recent console with the latest firmware and still get your error, you should contact Brett Lane, Davis' lead support person. His email is brettl@davisnet.com. I would think rounding errors should not occur, but if they do, a firmware patch would likely fix it.
I've got 3.15 installed, which is the latest. I initially emailed Brian about the issue, and he said that it seemed like a bug and that he would pass it on to the engineers to have a look at.
I've emailed him twice since, asking for any latest information, and I never got a reply back, so i gave up. I've never rated their customer service, even when I had Vantage Vue issues. The original seller didn't want to know, and said to contact Davis, and they didn't want to know either.
There's no point in contacting the original seller in this case, as it's problem with the firmware, so it's down to Davis. It seems, unless you live in the US, you have two hopes of getting help from Davis, bob hope, and no hope!