Thanks I had done a RFM factory reset before I did the update, I might go and try that cable just in case mine is faulty from jaycar.
Both 1.5 & 1.6 show in the pinball update manager and when I press update it gives me either fault code, I tried re installing, tried win 95/98 compatibility mode to no avail.
It's becoming an annoying project just to update to either firmware, I want to give up but I'm determine

Another thing from memory was that the update file had to be in the same directory as the installed update program.

But if the update shows in the list as you can see in the picture here then that's not the issue.

I think you can totally screw with all the port settings in the RFM setup screen, maybe try a factory reload in case someone has screwed with the port settings?