Various problems since upgrading from Domino 509 to 6

I am new to domino administration. I am a Network Engineer certified in exchange 5.5 and 2k. Suddenly I am thrust into administration of a newly upgraded Notes 6 Domino server. HELP!!!.. we have been experiencing the following: users with the notes 5.09 client can’t archive. Remote Administration locks up the server and crashes it. The Domino server crashes and takes down the router with it. Bizarre! Can anyone help me?

Subject: Various problems since upgrading from Domino 509 to 6.

After the upgrade, have all databases been compacted to ODS 43 ?

Subject: Various problems since upgrading from Domino 509 to 6.

what are the hardware specs of the server?any known issues from the 5.09 server?