Just a heads-up:
I found out the hard way that Sudocue's canonicalization routine will choke (as in, program lockup with no warning or error message) if it encounters a puzzle string with no clues (all zeroes). I inadvertently had one of these in a puzzle collection file, and it took quite a bit of investigating to figure out why Sudocue was freezing only a short way through canonicalizing the collection.