...When I go to Prefs and open "Picasso96Mode," I get an immediate popup stating "Could not find any modes!" When I hit "Ok," I see lots of options, but they're all grayed out, and I can't get anything to show on the screen connected to the Spectrum...
You won't see anything unless you have some modes in "Picasso96Mode". Is the box in the upper left corner (looks like a box with an arrow coming out of it) grayed out too? If not, try dragging it into the settings window. You should see "Spectrum (1): Village-31" appear in the setting window. The driver should have pretty much configured all of the modes for you then if you see that under settings. Picasso96Mode has a bizarre layout. If you have the Spectrum recognized then just click Save. You should then be able to go into Prefs/ScreenMode and choose a Spectrum mode.
If this does not work, hold down both mouse buttons and see if the spectrum is detected by the expansion board diagnostic;
Looking at my A3000 it is going to be one of the following:
Board Num: 2 Manufacturer: 2193 Product: 1 Status: Working
Board Num: 2 Manufacturer: 2193 Product: 2 Status: Working
I am pretty sure this is it. Gfx cards ususally come up twice.
Hope that helps.