Thanks, Mr. Todd.

You have put my thinking on a good track. It's not my program that's the whole problem, because when the dealer tried to make the thing work, with his own demo program, the MX3000 wouldn't work. Also, when I do a factory default and then re-load my program, it should work, as it did when first put in, and then fail again after a time, but it doesn't, it's belly-up from square one.

However my son, who's a skilled software person, points out that there may be a bug in the MX3000 operating system such that something in my program causes, over time, a build-up of garbage, which finally jams things up. In most cases, he says, going to the factory default should clear this garbage, but, in about ten percent of system programming this is not handled properly, so going to the default doesn't do it.

So it's maybe a combination of something in my prgramming and the MX3000 operating system that's the cause of the problem.

I'll see if the dealer can get the MX3000 prgarmmers to run my program and see if they can figure out where the bug is, but I kind of doubt that they'll be willing to do it.

Maybe there's a newer version of the operating system I can download and see if that fixes things.

Thanks again for a really good suggestion.