Accesing system folders on dual boot system

It seem i have inadvertantly locked myself out of my xp desktop folder.

An explanation:

I`am dual booting between XP pro and Vista ultimate, both installed onto
primary partitions on a single 500gb hdd(using acronis boot loader to select
OS)

The problem arose one day when i was trying to access my desktop folder on
the XP partition while working in Vista, I recieved the `you do not have
permission to access this folder` so I chose to click continue to gain
access.

After following the instructions on screen I was happy to of successfully
gained permission to access the folder.... but....

once i`d booted into XP pro I found I have locked myself out of the
desktop(getting desktop is not accessible), now I have looked around to try
to find a way to re-admin myself to the folder but I continue to get the
same desktop is unaccessable error!

I have tried to create a new admin account on xp in safe mode but even then
I cannot gain access to the desktop folder.

Anyone have a potential solution or do i need to backup my data and
reinstall XP?

TIA,

Pedro.