Route recalculation with updated map--855 trouble

I'm a mostly happy Nuvi 855 owner. Almost always I use simple navigation to next desired point, but in a couple of cases I do use a route. One case was to investigate the problem discussed in the [url=http://www.poi-factory.com/node/35007]Lane Assist Odd Errors[/url] thread. The other case covers a couple of situations where I've learned I like to take a different routing than the calculated one. Building a route with as little as one "forcing" waypoint allows me to get guidance the way I like to go.

End of preamble, here's the problem. I do understand, I think, that a route in the Nuvi is bound intimately to a particular quarterly map revision, and needs to be recalculated before being useful once the map in use updated. But on my Nuvi 855, not only does it not notice that the route is out-of-date and recalculate, or at least offer to, automatically, but it does not recalculate even when I got into route edit mode and press the recalculate button.

So far as I've stumbled on, I actually have to add or delete a waypoint, so that it will actually do a recalculate. Or, alternately, if I press the recalculate button and change the routing from fastest to shortest, then it will actually recalculate.

This seems odd, not to mention error-prone and annoying.

Have other 855 owners seen this?
If so--what is your preferred workaround?

Are other models like this?