Today I tried to use my Microsoft Lifecam NX3000 (a gift from attending a Microsoft Event...) but Jitsi crashed:
Grabber::SampleCB causes the crash because sample->GetActualDataLength() is less than the expected amount of data when the image is being flipped. A consistency check should probably be added here, as it might be the case that the available data is less than the expected amount anyway.
The root cause however lies in DSCaptureDevice::setFormat. Although the call to streamConfig->SetFormat(mediaType) returns S_OK, the format is in fact not being set (check by calling GetFormat again afterwards). Now whether this is documented or not, we should somehow cope with that. A thread in Microsoft's Discussion Forums  points to the solution: don't modify the resolution of an obtained AM_MEDIA_TYPE but supply one matching the desired format - obtained via GetStreamCaps().
If someone wants to debug on my machine - feel free to contact me directly.