OK I'm completely confused now.
I've had the SNRM at 3 now for over 30 hrs.
No errors, no dropouts (and substantial rain at one point)
It gives me a sync of 2432. Much better than with my Belkin, but still profile of 2M. ( I understand why - would need to increase sync speed substantially to jump up to next level)
So why would Virgin set me to an SRNM of 9?
Incidentally it seems to me that I might as well go back to SNRM of 6, still get 2M, and theoretically by more stable (although, short time I know, but very stable at the moment)