Windows XP can only record to drives formatted in the NTFS file system. This is the native PC format. Drives accessible via MacOpener or Macdrive are actually formatted in Mac OS Extended (commonly known as HFS or HFS+). This format is fine for transferring data to an NTFS drive, but is unsuitable for recording and playback.

To get rid of the errors, make sure your sessions are on an NTFS drive when using Pro Tools on Windows XP.