Start from kernel 2.6.39 my TV card's PV951 radio is not work.The problem appear by partial check for option "bttv radio=1". For that option /dev/radio0 is created but checking for radio into function check_mode() see only to device's flag ".has_radio", which clear for "ProVideo PV951 (42)" card.
On 2.6.38 it still fine work and form 2.6.39 to present it is not.
I have seen to source's different for BTTV code from 2.6.38 to 2.6.39
and have not seen any functional changes then the problem is generic for