Based on earlier messages in various blogs, it appears a few dvb-c viewers with STV0297 have tuning problems in some circumstances. I've resolved mine by modifying the frontend driver by increasing those timeouts that expire and adjusting the pwm value so that it gets locked also on QAM-128 modulated frequencies. I suspect some of the other register values are not treated correctly either, since e.g. reading the BER values does not give meaningful results. I don't have idea where to get the data sheets, I cannot correct those. br., Mika S.