figure this out for anyone interested, found an article from 2012 that outlines some registry key changes you need to make on you cluster nodes.
snippet taken from the article above.
Of the tests we conducted above the root cause of the short file name error during the Pre-req checks was found to be the fact that we were not able to remotely access the registry using the SQL Virtual name which we should have been able to do. On contacting Microsoft Support we were informed that there are known issues around NoRemap registry key needing to be set if you are using Network Name resource that is dependent on a separate new IP Address resource â€“ see http://support.microsoft.com/?id=306985
The final solution was to add a new REG_MULTI_SZ registry key to BOTH cluster nodes called:-
This key should contain the values of:-
After adding the above key and values we needed to reboot both cluster nodes and then we were able to connect to the SQL Virtual names (CLUSQL02 + CLUSQL01) using Regedit (Remote registry). Running the SCCM Pre â€“req checker now returns no errors.
Hope this soluton helps someone else.