Was working with Windows Server 2008 x64 but not any more?

I've had an Easycap working with a Windows 2008 Server x64 setup for a while. It basically just answers skype calls from the in-laws so they can see their grandson.

Back in November it just inexplicably stopped showing video. No upgrades to skype or the easycap drivers.

When I try bringing up the webcam properties in Skype, or the Video filter properties in videoview.exe I get the error:

Calling Syntek Mini-Driver function "Get" error

And then it brings up the Capture Properties window. But none of the settings are there. If I select any of them, like NTSC/M or S-Video in the Image tab I get a "Set" error.

I don't see anything in the Event Log. I'm logged in as the machine's Administrator.

If I keep fiddling with the properties window when using videoview I can eventually get it to show video. So the input circuitry IS working. It throws a "Get" or "Set" error each time, but eventually seems to force it's way into the right mode.

It would appear that the driver is not retaining the default values I need. Where are these values saved? Are they in the registry? Could I change the defaults so it always goes into S-video input using NTSC? I can see there are some settings in
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class\{4D36E96C-E325-11CE-BFC1-08002BE10318}\0010 (the last number presumably changing based on hardware present). There are some entries for TunerType and the like. But I have no idea what values will achieve my desired configuration. I have a feeling it's a registry permissions issue, but have no idea where to start looking.