SOAP-Error after suspending VM

Hello Forum,

when suspending my Virtual Machines (on a vMA version 5.1.0) I get this error:

Operation cannot be performed:

SOAP Fault:

Fault String: A general system error occured: Unknown error

Fault detail: SystemErrorFault

but each VM is suspended and also starts up again! Suspending via vSphere-Client works well. After setting up ESXi 5.1

some month ago everything worked without any errors, so I think, that one of the fixes for the ESXi causes this behaviour...?

Thanks in advance for your help!

Regards

martinelli