James Farrar writes:

PINs appear to have problems internationally. I've just got back from
two weeks in California, during which time I signed for all in-store
transactions, and if a machine (except an ATM) asked me for a PIN, it
rejected it (thanks, BART, amongst others).
--

Well, BART is not an organization that I'd expect to make things work,
but I've been told that only 4 digit pins are universal. Do you have
more digits?
I've never used a PIN in a transaction with BART, myself.

73, doug