I just learned a new factoid:
If I copy a page and rename it, but don't rename the Class name, then the two pages will compile and run in DEV but not in TEST.
The error message was bizarre: couldn't find the Eval or Bind verbs. When I fixed these, then it couldn't find the Title or MasterPageFile attributes. This got me thinking.
The solution of course was to rename the second class name to something unique.