It might be that they are just victims of their own success ... didnt they have a special offer during the summer/autumn where they had an $8 a month deal when you paid for some months in advance?
Can anyone remind me what newsgroup host VM use?
/edit
Bloody hell, giganews are now saying they have 522 days retention!!
looking at
http://www.newsgroupservers.net/ now, they say this about astra:
Astranews is something of an enigma wrapped in mystery surrounded by styrofoam peanuts. We've been tying to get in contact with them to learn more about their operation, but so far have had no luck. Their service has had intermittent disruptions over the years. Sometimes their website is slow or unresponsive. But they have a loyal following of subscribers. They certainly have low prices. Be careful of their unlimited plans though - the entry level newsgroup service rate speed limits you to 1Mbit / sec - OK for dial up or old DSL, but not for cable modem users.
To the best of our knowledge they run their own backend and front end, relying on no outside services other than to peer with the major providers to get their messages.