Strange stripes on captured images

Hello all,

	First of all, my apologies for sending two jpeg attachments to the
whole list. I am not able to leave them on any server so that they are
reachable for everybody. Sorry.

	I am using a custom bt878-based capture card and in the last days I am
sporadically capturing images with the effects shown on the pictures I
am sending. I would like to ask you if any of you ever experienced these
effects. The facts are I have three of these cards plugged to the PCI
bus of a Microstar MS6368 mainboard (VIA chipset), and input switching
is provided by means of an external analog multiplexer.

	I would really appreciate any comments on the subject, as I must admit
I am a little bit lost. 

	Thanks in advance for your help,


		Miguel Garcia

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