Turns out the thing was working as designed. Disregard the information quoted below.
Hopefully this problem is almost unique to me, since I just recently bought a boxed copy of Civ IV (which I believe was v. 1.09) and installed the v. 1.61 patch without the intermediate 1.52. Anyway ...
I was getting 60 resource hammers for clearing a forest, in spite of the v. 1.61 notes which indicated that this should have been changed to 20. I re-downloaded the patch and re-installed both it and the game itself; no effect.
So, after poking around the .xml files a bit, I came across something that seemed to be the source of the problem, and the fix I made so far has worked successfully. Here's what you need to do:
1. Open up ...\Assets\XML\Units\CIV4BuildInfos.xml with Notepad or some other text or xml editor that you are comfortable with.
2. Idiot proofing note: Make a backup!
3. Find all instances of ">30<" and replace them with ">10<". There should be twelve instances. (I didn't do it this way myself, because I had no way of being sure that the only instances of ">30<" in the file were the ones that need to be changed, but this does seem to be the case.)
4. Use "Save as ..." and select "All file types" to save the file under its original, .xml name, location, and format.
5. Go back to playing Civ IV and weep as all of the Wonders are built by AI before you have an snowball's chance in hell of building them yourself.![]()