For about a month I've been having problems with printer agents which either disappear completely or their configuration gets corrupted.
Every few days I find that people can't print on their printers. It seems that out of 18 printers I'm having usually one or two agents are completely missing from the manager and I have to recreate them with apropriate `iprntman printer -c ...' command. And most of the other printers gateway load command seems corrupted. For example, iManager shows (in iprint manager configuration) gateways such as "iprintgw PORT=LPR HOSTADDRESS=�". As you can see, we have a strange character after the IP, and the rest of the command just vanished. Sometimes it's like "iprintgw PORT=LPR HOSTADDRESS=����NTERNAME=PASSTHROUGH ".
When I connect to the iprint manager via WWW management interface it doesn't show the part after those strange characters at all, so it shows only "iprintgw PORT=LPR HOSTADDRESS=".
It usually happens during the night, so in the morning it's already in such state. I don't think I'm doing anything that should change the server's state in the night. Just network backup to another machine. (and nds dump).
Any ideas where to look for a cause?
I'm thinking about downgrading iprint, is this a reasonable idea?
For now I'm using

# rug info novell-iprint-server
Catalog: system
Name: novell-iprint-server
Version: 6.0.20080422-0.2.1

BTW, I tried restoring previous state by copying psmdb.dat, as one of TID's says, but all I get is information about deleted printer agents for which I can make a redirection.