I changed my CRT monitor refresh to 60Hz and it had no effect on Civ.
I'm fairly sure it's a refresh issue.
Oh. Sorry, I assumed you wouldn't be using a CRT monitor.
Seeing as you are using a CRT monitor, you're justified in assuming it's a refresh issue.
But I wonder, are you guessing that civ is somehow reducing the refresh to less than 60Hz? I've never heard of anything lower than 60Hz (except perhaps for PAL 50Hz CRTs).
I'm pretty sure flickering can offur if the refresh rates do not match, whether the one the VGA is sending is higher than the one the CRT is using, or vice versa.
If you changed the CRT to 60Hz and you suspect the game is using 60Hz, then theoretically it shouldn't flicker. There are two places you set the refresh rate...
1) Somewhere in vista, like the control panel or something. I know in XP you can just right click the desktop, hit properties, go to the settings tab, then hit advanced... etc. With vista I'm not sure.
2)On the CRT itself. I assume you found the buttons or whatever on the unit and successfully changed it to 60Hz.
If (1) and (2) both match I can't imagine why you'd get flickering.
Assuming the VGA output has the same frequency as the CRT is using, there should be no flicker.
Maybe your graphics card is somehow lying about the refresh rate it is sending to the monitor? Is the graphics card ok with Windows Vista? I know the card I have - a GeForce 8600GTS - is not suitable for vista.