duplicate primary index in bayes db from SpamAssassin

Dear list, I don't know whether pgsql-admin or the SA list is the
correct one to ask, so I start here. I have a bayes Postgres database
for SpamAssassin, which I use shared from 2 servers to have the same
content. I think this could be a locking issue or whatever, I don't
care. BUT: I have lots of "duplicate index" elements now, preventing a
restore or cleanup. Here's the dump and diff if anyone cares:
http://zmi.at/x/bayes_dup_idx.dump.bz2 (upload currently running)
http://zmi.at/x/bayes_dup_idx.diff.bz2

Could the problem be caused by any settings to the DB, or because of the
stored procedures? Normally there should be no way this can happen, so
what can cause this?

mfg zmi
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