I'd done over 150 miles on the new cluster when I started the thread, so don't think it's that.
I've found that the highline menu doesn't work either. I've fitted a MAX CCCM and a 30 byte CECM today and they haven't cured the problem. I guess it must be down to the coding? Also, with fogs sets a DRLs, I get the little green fog symbol on the speedo! Really not sure what's up with this. I've spent hours today trying to sort it!