This is actually an issue with how vmware-cmd was written to parse the path when it's specified in the following format: "/vmfs/volumes/....". The script assumes that the VM folder is at the root of the datastore and no sub-directories are used to further separate it, there is a reason when you create a VM it's stored in the root of the datastore unless manipulated manually.
What is happening is the actual path to the .vmx file is being left out. Since the script is just a Perl script, I added a print statement to show you what it was getting for the $vmxpath variable.
Here is an example of a good register:
$ vmware-cmd --server olga --config .primp-olga -s register "/vmfs/volumes/4c575995-6d0ee178-89c1-001f29c948f8/test/test.vmx"
register() =1
DEBUG: \[vmStorage.dev-50\] test/test.vmx
As you can see, it takes that VMFS path and actually translates it to it's internal format which is in the form of:
\[datastore name\] vmfolder/vm.vmx
Here is an example of a bad register where a sub-directory is used:
$ vmware-cmd --server olga --config .primp-olga -s register "/vmfs/volumes/4c575995-6d0ee178-89c1-001f29c948f8/development/test/test.vmx"
DEBUG: \[vmStorage.dev-50\] development/test
Fault:
SOAP Fault:
-
Fault string: A specified parameter was not correct.
Fault detail: InvalidArgument
A specified parameter was not correct.
As you can see, the development folder is parsed but now the test.vmx is left out and hence it's consider a invalid input and the SOAP fault is thrown.
Without having to edit the script to fix this problem, assuming you figure out the correct regex, you can actually use the expected format to register your VM. I don't recall if this is documented in vCLI references but I know it's not common knowledge unless you work with the APIs 
You can also register the VM by using the follow form:
$ vmware-cmd --server olga --config .primp-olga -s register "\[vmStorage.dev-50\] development/test/test.vmx" \[vmStorage.dev-50\] development/test/test.vmx
register() =1
As you can see here, if you specify the alternative and the true syntax format, you can get your VM registered even if there are folders between the root datastore and your VM configuration file.
Give this a try and it should work without any modifications
=========================================================================
William Lam
VMware vExpert 2009,2010
VMware VCP3,4
VMware VCAP4-DCA
VMware scripts and resources at:
Getting Started with the vMA (tips/tricks)
Getting Started with the vSphere SDK for Perl
VMware Code Central - Scripts/Sample code for Developers and Administrators
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