Yes it did - but they did that by sorting out a hell of a lot of memory management issues, that affected a multitude of game aspects - not just basic RAM vis performance. The Board was in Meltdown mode pre-V1.52, now its back to the usual gently simmering .....
Hence trying to make sure you only loaded from the discs and only loaded from the Offcial 1.52 Patch, not Direct2Drive's patch.
Stay with V1.52 come what may, not using it will only mask true issues as things proceed.
The mystery is why its not finding the game from the Patch - there have been issues in loading from some CDs & DVDs, but not come across not loading from the Patch before ....
If you Ack this post so your name is in the post list on screen, and hang on, there's a couple of guys who usually come in about now - to an hour from now - who could take you thro other stuff. Please keep the installation clean as is, or at the least tell em any changes made
Dont go crazy on the Registry - its very rare to have a civ problem there ...
Regards
Zy