Current JDBC Driver char encoding - Bug or feature?

Hello Postgres & JDBC gurus,

we recently upgraded from jdbc7.0-1.2.jar to jdbc7.1-1.2.jar (prebuilt
downloads) and now non-ASCII characters display as ?. That is not the
case with the old driver, I switched drivers back and forth to verify
this. Postgres is Version 7.1b4 on RedHat and was built with --enable-
locale but not with --enable-multibyte or anything else differing from
the default config.

psql displays that characters correctly when printing query results.

Any hints what we can do about this?

Can't imagine that I have to reconfigure the backend when the JDBC driver
changes.
We can't fall back to the old driver because of various other bugs or
unimplemented methods there.

Please forgive if that issue was answered already, although I found some
related messages stating that 7.1 is encoding aware and has to have the
right encoding, I didn't find anything about relating changes of the JDBC
driver behaviour. I just want to be sure what to do, before going to the
length of exporting - rebuilding - importing when the issue is possibly
not related to the backend at all.

TIA, jan

--
Jan Wessely
Vienna Knowledge Net
mailto:jawe(at)vknn(dot)org
http://www.vknn.org