i tested the issue by flashing the device and leaving it on for a reboot. if it was a firmware corruption, it should have come up clean on the reboot - because the device stayed on. but, it didn't. so, it's an error that's happening when windows recognizes the device. and, because it's not happening on the flash, it has to be the result of some kind of corrupt registry setting - because everything else would be the same, whether it's rebooting itself on the flash or being read as a device by windows.

when i do the reinstall, i'm going to try and clean as much out of the registry as i can get out of it - and i do think i can probably get this to work. but the class installer uses long strings of numbers that are difficult to track down.

i can't explain why this wasn't happening previously - except that it maybe was, and i didn't notice. which is another layer to keep in mind as i'm reanalyzing material.

the other thing is that i have a vague recollection of deleting the filters on the install a while back. so, those filters might have been gone for quite a while. i can't clearly remember. that's something i can script, and should so i don't forget.

the driver reinstall helped substantially, but it still seems a little distorted, so i'm going to reinstall a final time - i feel i have to to be sure i've actually hit the root of the problem. but i think i'm starting to finally get my head around what actually happened.

1) i think i cleared out the registry on the last reinstall, some time ago - whenever it was. spring of 2014, maybe.
2) then at some point in may i put that file back (streamci.dll).
3) on a driver reinstall (these are done from time to time, to deal with funny plugins), that screwed up the registry.
4) when i deleted the clock before, it didn't matter - because i wasn't really using it for this device. but, the combination of the driver install and the undeletion of the clock created a conflict. i suspect i should be able to reinstall the clock after i stop the drivers from entering that information into the registry.

the root cause of all of this, then, seems to be the driver install with the streamci.dll in place. i suppose i may have exaggerated something with that codec install, but it wasn't the actual crux of the problem.