'96 distributor/rotor mismatch?

[Steve Barber]

I ran into a problem tuning up my wife's '96 SE-R recently: the
new rotor doesn't seem to fit on the distributor shaft.  (The cap
did fit however.)

I verified with the dealer that the rotor I have is the correct part
number, had a different guy look it up even, therefore I suspect a
previous owner put the wrong distributor on it.  However, these parts
guys don't seem to have ever actually looked at any parts (clueless),
so I'll check the part # against se-r.net when I get home as a 3rd check.

The rotor that's currently on the car has a slightly differently
shaped socket, and the flat that matches up with the flat on
the distributor shaft is narrower on the new rotor such that it
doesn't quite fit onto the dist. shaft.

Are other distributors known to fit/work?  I have noticed some weird
non-linear throttle response compared with my '92 but had always
written it off as high-port/low-port differences, not having driven
other low-port cars.

Thoughts?

Steve