not sure if this is the same as you issue but it sounds vaguely similar. I stumbled accross this the other day.
By default, Windows Terminal Services clients do not have write access to the registry on a Windows Terminal Services computer. To run some Outlook features, you might need to give users write access to some branches or keys. For example, to allow users use of custom MAPI forms for Outlook 2002, unlock the HKEY_CLASSES_ROOT\CLSID branch of the tree.
To give users write access to registry keys for Outlook
Log on to the Terminal Services computer as the administrator.
On the Start menu, click Run.
Type regedt32.exe and click OK.
To allow users to use custom MAPI forms, in the HKEY_CLASSES_ROOT window select CLSID.
On the Security menu, click Permissions.
In the Registry Key Permissions dialog box, select the Replace Permission on Existing Subkeys check box, and then click Add.
In the Name box, click Everyone, click Add, and then click OK.
If you do not want to give all users this access, you can add specific users or groups of users in the Names box, rather than selecting Everyone.
In the Type of Access box, select Special Access, and then select the Query Value, Set Value, and Create Subkey check boxes.
Click OK and close the Registry Editor.