There's a change in the memory manager -- including functions such as ZwMapViewOfSection and MmMapLockedPages, in Windows XP®.
In the past (on NT V4 and Win2K), it was up to the driver writer to ensure that the same physical page was not mapped with different caching attributes. In other words, it was possible to map the same physical page with different caching attributes. This is an error, and can lead to corruption of the page.
In Windows XP, the memory manager catches this problem: That is, when mapping the same physical page, the page must always be mapped with the same caching attribute. If this is not done, the function returns STATUS_CONFLICTING_ADDRESSES.