New insurance company methinks.
I'm with h&r, my ncb carried over from prov to full licence. Having said that, I have coming up on 6 years worth and I'm still the wrong side of 250 tpft for a mk1 fzs 6. I got a quote from mce for a 07 speed triple 1050. Fully comp was about 235 or summat. I know i'm getting bumped but h&r are always a pleasure to deal with and I think thats why I've stayed.
When I get the gixxer on the road, they quoted me over 400 for a 2bike policy, cancelling my current. I reckon I could get cheaper on comparison sites but even then, 2 fast, nimble and agile bikes in good nick for 400 ain't too bad a deal either.
Your ncb should be valid. They are talking shit. Threaten to take the business elsewhere and see them change their tune