ESXi 4.0.0 Wrong Available Space for DATASTORE on DELL 2950

Hi Community

Well We have just brought new DELL 2950 Server , with following Hard/w Config.

750GB x 6 SAS Disk , RAID 10 configured.

2 x 2.83 Quad Core Xeon Processor

32 GB RAM

we have installed ESXi 4.0 , and use the client vSphere for Managing host , our problem is when we try to add "datastore " it always shows only 45GB space available , while Storage contoller shows correct disk size as 2.0T , we have tried rescanning and refershing the controller and Disks , but nothing helps ,

Any suggestion on how should we make our 2.0T disk as available space for DATASTORE ? Please see atacched JPG for problem

Regards & Thanks

Server_Sap