When connecting a list to Outlook 2007, Outlook creates a PST file in C:\Documents and Settings\%username%\Local Settings\Application Data\Microsoft\Outlook\ called "SharePoint List.pst" or "SharePoint Folders.pst". When you are using Roaming Profiles, the Local Settings directory is not copied along with the profile. This sounds logical, because the PST can become very large and you don't want this data to be copied to the server.
But, and here is the catch, if a user logs onto another workstation Outlook does know it has connected to a PST file before and tries to open it. Because the file has not been copied with the profile, it does not exist.....presenting the user with an error message.
On the blog of Jose Barreto I found a post which explains how to disable the Outlook integration. By entering a key in the registry, connecting Outlook to SharePoint is not possible anymore. This will definately solve the issue, but will also prevent user from using the Outlook integration. Something I do not like.
After some more Googleing I found the Office 2007 System Adminstrative Templates on the Microsoft site. When importing them into a Group Policy, you have the possibility to configure some settings for Outlook 2007. And then especially the two following settings:
User Configuration > Administrative Templates > Microsoft Office Outlook 2007 > Tools Account Settings SharePoint
- Do not allow Sharepoint-Outlook integration
- Do not roam users' SharePoint lists