So I took a SharePoint 2007 SP2 compliant and tested content database and placed it into a SharePoint 2010 enviornment. All the content was there. The permissions were fine. However, by database attachment went to a new SharePoint 2010 web application that had a different URL name.
Example: intranet.company.com SP 2007 content database was attached to sp2010dev.company.com
This URL change throws off alerts. You can delete the alerts and add them back in but that is just crazy to think about that scenario. And guess what…..there is a PowerShell commandlet to fix this issue. But unfortately, this answer is buried on search engines.
Anyway, there is the PowerShell commandlet.
[box]Invoke-AlertFixup -site <NewURL> -oldurl <OldURL> [/box]