For the first issue, Please check KB69037.
For case 1, ePO relies on the AgentGUID value and MAC address for determining whether a machine needs to be added or updated. So IP Address value is what ever is reported by the Agent. If the MAC address of both entries are different then they are different physical or vitual machines.
For case 2 & 3, please post on separate threads withdebug logs for Agent log and server.log on the ePO server with matching timeframes - which may help find out what is actually going on.
Thanks for the reply . yes the GUID was diff for those Hostnames. we also thought that the issue can be becausse we use IOS imgae pkg to build a system so we thought the ePO agent is also included in that pkgso it must be cloning in some way , but checked with wintel team and they told that the ePO is installed after the complete systems is ready with windows OS and then they install the ePO agent so we negate the duplicate due to this installtion process.
Reg logs will sure post once i get that .