INN 2.5.2 Anomalies

[Martin Pirker]

Hi list....

The local INN started acting strange lately. Everything runs fine
until at a certain point INN decides stop producing data, e.g.

->LIST ACTIVE *
<-503 No list of active newsgroups available

->ARTICLE 12345
<-423 No such article number 12345

->ARTICLE <whatever>
<-400 NNTP server unavailable; try later

Thing is, if one closes the connection, immediately opens another
and runs the same commands again, it works just fine.
I've not yet tracked down a short command sequence for reproduction.

Unfortunately, some 5+y old code depends on a proper working
INN server and thus now is broken and needs to be fixed - fast.
This behaviour coincides with an upgrade to 2.5.2, however this
is not proven to be the cause.
This is a production system, so random patching and trying is no-no.

Digging into INN sources, e.g. the 400 with ARTICLE appears to be
related to history. History was rebuild on the server and things still
happen.

My question:
Anyone with other good ideas what could be the cause that
INN is acting like that? Seen this before somewhere?

Thanks,
Martin