CRM 2011 - Caller is not an owner for SubscriptionID Error

Over the past few weeks my team has been working on reviewing and revising our CRM environment in preparation to migrate to CRM 2011. As part of the preparation we have been testing the offline client and in doing so one of my devs ran into the error message of "Caller 2222222-2222-2222-2222-22222222 is not an owner for SubscriptionID 00000000-0000-0000-0000-000000000000" when attempting to go offline.

Now this odd as my devs CallerId\SystemUserId was 11111111-1111-1111-1111-111111111111 and not 2222222-2222-2222-2222-22222222, which is the SystemUserId for our TestUser1. So why was the outlook client making a call as another user? Well I after doing some initial investigation I conclude that it would just be faster to reconfigured the Outlook client, so we started the configuration wizard and typed in our server URL and hit the ‘Test Connection …’ button.  However, when it finished it showed that my dev authenticated as DOMAIN\TestUser1.

What! How is this happening? So I ask my dev, "Are you logged in as DOMAIN\TestUser1?" To which he replies, "No."  Okay, so how was the Outlook client getting another user’s credentials when it authenticates against the CRM server. Well it turned out that my dev had told IE to store the user name and password for Domain\TestUser1 when he was testing the CRM 2011 web client. We found this by going to Control Panel > User Accounts

And then clicking the ‘Manage Passwords’ button on the Advanced tab, which displays after clicking ‘User Account’

Clicking the ‘Manage Passwords’ button displays a form that lists sites that have user name and passwords saved.

When I clicked on the entry for crm.domain.com I saw the following

So to remove the entry we just selected the row for crm.domain.com and clicked the ‘Remove’ button. Once this was done we were able to reconfigure the CRM Outlook client and have it authenticate as my dev.  He wa then was able to go offline with the CRM 2011 Outlook client.