multiple open()'s on the same device

Hi,

I am playing with a Bt878-based card, which has 4 input sources. Actually, 
using bttv 0.9.11, I can open() the v4l device twice, but I can't capture 
data using different input sources (television on app1 / composite1 on app2).
Is this possible on the current status of bttv drivers? Please note I didn't 
try this with applications other than xawtv.

Thanks in advance,
Lucas