Logitech Webcam w/ Windows 7 black screen issue

[ThePengoose]

I am posting in hopes that someone else has seen this or might have a idea of what going on....thanks in advance.

I have a video capture application which uses the Logitech C600 webcam as the capture device and it has worked for some time. Within the last few months I have began seeing issues on some Windows 7 machine, including GraphEdit. The problem is that webcam is found and doesn't appear to failed any of the the additional filters that are created (avi decompressor, color space, etc.) however the image that is displayed in my app is black. The camera LED comes on  as it always has and from everything I can tell it is operating normally.

I also built the graph in GraphEdit Plus and all filters and pins connected fine, the video render pop-up, and the time bar began moving when pressing the play button....no errors at all, however it still shows a black screen. The same application will run fine on XP and various Windows 7 machines but does have this issue on about 1/3 of the Windows 7 machines I have tested it, in both 32 & 64 bit flavors. I have updated all the drivers and Windows Update. The webcam works fine using Logitech's software....

I have tried to connect to the running graph but I get an exception in GraphEdit......

Any Ideas? I have tried virtually everything.

[Dee Mon]

Looks like camera driver issue...
I would insert a sample grabber right after the camera filter and watch the data coming. If it's all zeroes then there's nothing we can do via DirectShow, it's the problem of driver and hardware. But if there is some data but it's not shown due to zero alpha channel arising somewhere or other reason, then it can be cured.