UTF-8 -> ISO8859-1 conversion problem

ERROR: could not convert UTF-8 character 0x00ef to ISO8859-1

Running 7.4.5, I frequently get this error, and ONLY on this particular
character despite seeing quite a bit of 8 bit. I don't really follow why
it can't be converted, it's the same character (239) in both character
sets. Databases are in ISO8859-1, JDBC driver is defaulting to UTF-8.

Am I flubbing something up?  I'm probably going to (reluctantly) convert
to UTF-8 in the database at some point, but it'd sure be nice if this
worked without that. :)

thanks!