I am capturing VHS tapes with either of two BT 878a based PCI boards. Everything had been going great - finally, after many tedious problems which I sorted out. I was captuing using the BTWincap drivers, and the bundled version of Amcap. I capture through composite.

Suddenly, as of a few days ago, I got a darker band accross the bottom of my picture - other than being a little darker it all looked nice.

Thereafter, I have checked everything I can think of, very methodically. Please, please help Me!

I only have one other PCI card which is a 2mb ATI rage IIC vga card. I am pretty sure that it is not conceivably any kind of PC hardware fault - reasons to follow. It must be a setting - but what?
I use Windows XP SP2. My board is Intel DP965LT

I have tried in many combinations:

Totally clean installs - with or without various updates and different versions of drivers. Different BIOS versions all carried out properly. Swapping the VGA card to different slots with either of the 878a capture cards. Different video player - and different scart adaptor / composite capture cables. Different 878 drivers and DSHow capture progs!!! Different BIOS settings.

When I say I have tried the above, I mean painstakingly - and it was all working fine before, now EITHER of the cards (which I only have had one in at a time) just get this darker band accross the bottom - what the hell causes it???? How can I get back to my even picture?

Thanks so much if anyone helps!! My mind has almost snapped when this infuriating problem has appeared and I run such a clean tidy system.

Please look across the bottom of the screenshot , it doesn't show up so much on pure black but it is always there on anything.