OVFTool not working at all

I just downloaded ovftool and installed it on our vCenter server (VirtualCenter 2.5) .  I'm trying to convert a VMX to OVF and when I run the tool it tries to open the VMX source and then just returns to the command prompt.  No error, no warning, no output at all.

Here is my command and the output:

C:\tmpflux\Symantec_Brightmail_Gateway_8.0>"C:\Program Files\VMware\VMware OVF Tool\ovftool.exe" Symantec_Brightmail_Gateway_8.0.vmx C\tmpflux\newbm\test.ovf
Opening VMX source: Symantec_Brightmail_Gateway_8.0.vmx

I've tried adding the source type and the target type switches, I've tried just probe mode (not sure if that will work on a VMX machine), I've tried moving the VM files from the network to local machine and tried moving them to another drive on the local machine.  Nothing happens at all.

The VM is a Symantec Brightmail Appliance downloaded from Symantec's site.  The source VMDK is a 2 GB Max Extent Sparse disk.

Is there a verbose switch to ovftool that I can actually see what it's doing or log the verbosity to a file somewhere?  Is the VMX file jacked up?  Am I missing something REALLY obvious?

Thanks for your help,

Flux.