I don't know if the following experience may help you, hope so...
After a LOT of problems with my old PC - the one used only for analog captures, after the new PC arrived - I finally managed to solve them.
First of all, I use VirtulDub for capture - I tried a lot of other softwares, and this is the best of all, at least IMHO. But it's not perfect, of course.
A very good feature of it is it remembers the last used capture settings; a problem encountered several years ago - that I forgot completely - is that, if you select the digital audio as input, and do not connect a digital cable AND a digital audio signal, it will stuck and never work.
Apart that, the other problems arise with the latest capture card I acquired, an AJA Kona LS. It was shipped with its own software, Machina, but, albeit working, and offering some options not found on VirtualDub, it's still barebones in a lot of other settings in comparison.
VirtualDub refused to display the preview, and also to accept any video input. I tried everything. Then, once, by chance, I discovered how to let it work. First, open Machina; it will recognize (obviously) its own capture card video signal. Close Machina. Open VirtualDub. Now it is able to recognize the hardware... don't ask my why!
So, *maybe* there is a chance your hardware works well only with its own bundle software; or, that another software misrecognize the hardware as is, but the bundled software *may* trigger the hardware, so the previous software will recognize it properly... try to do some tests, and good luck!