Hi Lugh!!
Try looking at HKEY_CURRENT_USER\Software\Business Objects\Suite 12.0\Components\EnterpriseLogonControl
The Key Names you'll want to add are:
LastApsName - put the CMS name in here.
LastAuthentication - put the authentication type here. Default is secEnterprise.
The additional keys that I see in mine are LastUserName which is the BO user id last used to log in and UseApsNames which is a semi-colon delimited list of all of the CMS' that I've accessed (I have access to BO in three distinct environments - local, Dev server, and Production.)
I hopw this helps!
-Dell