for me, these kind of problems (same card as you have) seem to be
vanished since using this patch
https://patchwork.kernel.org/patch/244201/ this is not yet included even
in the 2.6.38 kernel which I'm using now. Btw, another one useful for
getting at least some indication in femon with this card is this one:
http://www.mail-archive.com/linux-media@vger.kernel.org/msg22085.html