Well, with the announcmentsof Civ4 soon to come, I searched in the drawer for that wanted Civilization 3 CD. Installed it, then installed civ3 Conquests. Then I installed the 1.22 patch for it. And then I got the big message :
btw unpatched vanilla plays fine

ok, I patched vanila, ptw and conquests.
vanila plays normally
ptw crashes with the error above
conquest crashes with the error above

Try the advice here (http://www.atari.com/us/support/newfaq/civilizationiiiplaytheworld.php?browser=1&issueNum=409&osType=WINXP&pageDisplay=MAIN#faq_prodissues).

Manually copy font
You may need to copy a font file into the Font directory

1. Double-click on My Computer. If you don't see My Computer, click Start then My Computer.
2. Click on C:\
3. Click on Program Files
4. Click on Civilization 3
5. Click on PTW
6. Locate the file named LSans.ttf
7. Right-click on it
8. Choose Copy
9. Close this window
10. Double-click My Computer
11. Click on C:\
12. Click on Windows
13. Click on Fonts
14. Click on Edit
15. Click on Paste