'Invalid name' failure when creating snapshots

[Martin Stanjer]

We are running Virtual replicator 3.0A on four W2k servers on an MSA1000. One server has a pool containing only one virtual disk from which it is impossible to create a snapshot except when using the GUI 'new' option (which works just fine). The GUI based scheduler (which we intend to use) will create a job which appears to run, but the snapshot is not created, nor is there any event logged. If we run the snapmgr command in a dos window, it returns a failed message with the explaination that 'the specified name is invalid'. The parent name is correctly listed in the GUI and by the 'virtualdisk' command, and the snapshot name can be anything with the same result.
I'ts a live volume, so we havn't tried tweaking anything in the registry yet.
Any ideas please?