I had the same problem (PST files on my local Mac drive that were unaccessible by Outlook or X1), and struggled with it all day yesterday. I am using shared folders in Windows 7 in Parallels on a Mac running Snow Leopard. The latest update to Parallels caused my X1 email-search software running in Windows to no longer be able to access my archived Outlook PST files on the Mac shared Y drive. I accidentally found a solution to my problem before finding this discussion on the Parallels forum, which was to increase the Virtual Windows C drive size, and move the PST files to the C drive. Then they were accessible.