Can't create NSS Pool with iManager in Vmware/SAN.

[gordon_mzano]

This issue is similar to a previous post but we have a virtual server and SAN to complicate things...

The setup is OES2 SP1 running as a VM on ESX server with about 10TB of SAN storage. Some NSS volumes are running already, and were setup up pre OES2 SP1 (not sure if this is a factor), but now I can't create a NSS pool and volume in iManager, I get this error:

Error: The selected segment is not available. Select pool segments from free space on an unpartitioned device or an EVMS-managed device.

In iManager I have selected Pools from the Storage menu and then selected my server followed by New to create a new pool.
I then entered a name for the pool followed by the used size (mount on creation is ticked).
When I select Finish I get the error.

I've tried with NSSMU and explored with EVMSGUI, to no avail.

Most advice about this error relates to using a separate disk for NSS, but we have this (a virtual one). Can anyone suggest why we have this issue, or is there a trick to setting up NSS in a ESX virtual server / SAN environment? Would it help if I posted any of the storage config?

Regards
Gordon