Both tuners (A and B) in TbsCIapi.dll

Hi!
Does TbsCIapi.dll (StartCI) supports only one tuner (A or B) at the same time??? Because, when I call StartCI (after filter graph is started) to both of them (A and B) samples from tuners are not dumping! Or I do something wrong?
Please, help!
Does TbsCIapi.dll (StartCI) supports only one tuner (A or B) at the same time??? Because, when I call StartCI (after filter graph is started) to both of them (A and B) samples from tuners are not dumping! Or I do something wrong?
Please, help!