ERROR: Invalid criteria in Rule 2. Error near '�': Invalid command '�'

I have several screens which produce the above error. I can’t see anything wrong with the rules it objects to. What is really strange is that the offending screens work (and produce sensible output) when they are in a Screen of Screens.

Anybody else seeing this error?

Characters beyond the US-ASCII range (e.g. £) are not currently supported by the system and may produce unexpected results.