I cannot reproduce your findings?

I also can "reproduce" it only sometimes (can we call it "reproduction" then?). It happens a bit more frequently, if there is not much "activity" on the file system between deleting the file and re-creating it. The observation could be employed, if Windows XP would employ kind of a "lazy delete", i.e. if deleting would only mark the file in the directory as being deleted (which is how deletion is likely be done anyway), AND if a new file of the same name is created, just remove the deletion marker and leave anything else as it was before - including the ctime.

In Unix-speak, I would say that it just reuses the inode and forgets to update the inode modification time stamp. Windows doesn't have, as far I know, inodes, but maybe some similar feature....