Vista - UAC & PST File Access

I just installed 5728 on a dual boot system. I also installed the Office
2007 Beta Refresh. Since I am using a dual boot configuration with office
installed both on XP SP2 and Vista, I would like to share the same PST
(located on my XP drive).

When I try to access the PST from Vista, I am told that I do not have the
permission do so. After turning UAC off, I can access the file. If I turn
UAC on again, I cannot access.

Could anyone tell me what I need to do to access this file without turning
off UAC.

BTW: I have faced similar issues in different areas. It seems that unless I
access data or store data where it was intended, I sometimes run into access
denied situations.

I would like to work with UAC, but it seems difficult to achieve this when
you manage files on different drives and locations.