What happened to the "&&" operator?

I'm just installing 6.5 and I did a dump/restore of a database that I
had in 6.4.2.  This database has a field with a box type which is
indexed with an r-tree index.  The dump/restore went OK, but when I
tried to run a query against it, I got a weird error:

ERROR:  Operator 500 must have a restriction selectivity estimator to be
used in a btree index

This may not seem like a weird error to some, but why am I getting a
b-tree error on an r-tree index?
Anybody know anything about this?