Hi Leo,
I tried my IC92AD with version chirp-daily_12072011 on windows 7/32 bit - I was able to save and reload a file in .chirp format with no trouble. The XML files that usually cause that error for me ( if they are missing ) are all in the same folder as the chirp executable with the win32 distribution. There are three files: chirp.xsd, chirp_banks.xsd and chirp_memory.xsd. I'm wondering if you have a corrupted download.
I will try it with XP next on a virtual machine.