.tif file association lost after logoff/logon in citrix session

Hello

I’m trying to resolve an issue in a citrix environment where .tif files default to opening in MS Windows Picture and Fax Viewer. I have tried many a google search and am unable to find any information on resolving this.
What happens is:
Logon to citrix session.
.tif files opening with Windows Picture and Fax Viewer by default.
Change file association to open with MS Office Picture Manager.
.tif files open in MS Office Picture Manager whilst logged into the current session.
After logoff/logon the .tif file association reverts back to MS Windows Picture and Fax Viewer.

I would really appreciate some assistance on this as I am completely lost. Is there a registry key I can write to that sets the file association when a user logs on?

Thanks in advance.