First off i would like to state that i had no desire to buy vista...its all my school would let me buy from them. now on to the problem...by bts is patched to 1.03 currently as i can not find a 3.13 link.
when i played bts on my old computer with xp i had no problems with the mods or anything. now that ive reinstalled it on vista i have not been able to play a single mod successfully. My first try was the max riga mod. That mod actually started up and let me play about 20 turns. then on turn number 21 i continually got a crash. So then i tried the europa mod. That mod failed to even start. Then i moved on to the history in the making mod which looks pretty sweet. That mod starts up and lets me begin a game...but it fails to restrain the number of ai for some reason. i tried an 18 player game on huge and that crashed. i tried a quick game and that crashed and then i tried a scenario and that crashed. I am currently reinstalling all of civ4 for the 2nd time in a row. does anyone have any idea why god wont let me play bts?

It's not a problem with Vista, Civ IV works fine with it. Just hit the "check for updates" in the menu to update to 3.13.

It may be a DirectX issues. Once you have BTS installed, go into the Advanced menu from the main menu and check for updates. Version 3.13 will download from there and then install. I think that version contains a DirectX check and update, so that may fix your crash issues.

"Vista is perfect, there are no bugs in vista, this is just lies, we are in control of the interface, I repeat there are no bugs related to Vista"

-Microsoft Minister of Information.

Vista is perfect, there are no bugs in vista, this is just lies, we are in control of the interface, I repeat there are no bugs related to Vista

Except they self-document bugs, it's no secret, I haven't been keeping track of the exact number though.

It's better than XP, and in any case, nobody is being forced to use it.

by bts is patched to 1.03 currently as i can not find a 3.13 link.
There's three links for it on the civfanatics main page on the announcement of the patch, there's a link for the patch at the top of the main page, it's available from civ.com (downloads section), and you can get it from in game via going to main menu ->Advanced ->Check for patch.

Also if you haven't updated are you sure that the mod works for non-patched Civ4?