There were some subtle concurrency issues fixed "fairly recently"
(i.e. I don't remember the exact release) but they were very rare.
Certainly my live server didn't see them, nor did openacs.org, nor
any number of other sites (including SourceForge if you're right
about the version number because Tim originally switched to the PG
7.1 *beta*, brave man!)
I'm not trying to belittle the problem (and PG 7.1.x is much, much
better than Pg 7.0.x anyway, regardless of concurrency issues) but
it only cropped up for a handful of people over many years of use by
many, many users.
Things like this are why we keep nightly backups. I've had Oracle
hose itself on me but never PG. Not to knock Oracle, which is has
tons of features some folks need (intermedia and document filters
for MS formats, etc, that are reliable) and is after all very, very
stable.
My point is only that even very stable RDBMS platforms can choke and
whatever you use, be prepared with a backup strategy matched to your
needs (in my own personal space, once every 24 hrs).
