See if you can figure out some sort of pattern for when it works.

In my case, on my Mk2, I think there is something wrong with the IR sensor so that it doesn't work when it is in a particular temperature range. So the remote works fine when I turn the unit on, but then as the VFD starts heating things up the remote stops working. After a while it gets even hotter, and then everything is happy again. I haven't heard of anybody else having this problem, but I'm pretty sure that's what's going on in my case.

Is your problem anything like this?

It's a bit annoying, but I don't want to be without my car empeg for the week and a half it will take to send it backwards and forwards to England. The next time I go on a holiday without my car, I think I'll send my empeg on a holiday too!

Richard.