Changing existing NW 8.0.1 from client to storage node fails

I have an existing Windows Server 2008 R2, and I recently upgraded this client from 7.6.x to 8.0.1, as well as updating the NMM module from 2.3 to 2.4.1.92.

This update went reasonably well, and backups continued to work roughly as expected.

Now, I plan to have this and a few other servers becoming Dedicated Storage Nodes, so I reran the setup for NW 8.0.1 and selected "Change". I select "Storage Node", run through the wizard which then ends with "Installation was not successful. You can retry at a later time." or words to that effect. Not that many clues on what went wrong.

Incidently, I ran through the same process on another server with success, eventhough I had to reinstall the NMM 2.4.1 module before VSS backups would work. These are Exchange servers, if relevant.

The only difference between these servers is that on the server where it worked, two regular Qlogic HBAs are used for SAN connectivity, whereas the troublesome server I have Emulex OneConnect (The HP Blade OEM stuff). Worth mentioning because I saw something about  hba register error 0x5. I can't remember the exact wording, it was on a pop-up dialog box and I've not been able to reproduce it.

I've searched what I think are the MSI log files, and some extracts:

get_install_info: productname='NetWorker'

get_install_info: productversion='8.0.1'

get_nmc_product_code: entry

get_nmc_product_code: component_code='{A33F8DC5-361C-11D6-B364-00B0D0A2099F}'

get_nmc_product_code: Error calling MsiGetProductCode, status=1607

langpacks_to_install: Error calling MsiGetFeatureState for de_Feature, status=1606

I haven't select any language packs for installation.

The final error in the Windows Event log is:

Windows Installer reconfigured the product. Product Name: NetWorker. Product Version: 8.0.1. Product Language: 1033. Manufacturer: EMC Corporation. Reconfiguration success or error status: 1603.

Any ideas?