After using the Office Outlook 2010 keyboard shortcuts to navigate to the next or previous e-mail message, additional keyboard shortcuts will fail to respond. This issue only occurs when the Microsoft Dynamics CRM 2011 add-in has been enabled and configured.
Microsoft has confirmed that this is a known issue.
This issue will be addressed in the next major release of Microsoft Dynamics CRM.
To work around this issue:
1. Add the Previous Item and Next Item to the Quick Access Toolbar in Outlook using the steps in this article:
Customize the Quick Access Toolbar
2. When hitting the Alt key, you can see the keyboard shortcut that corresponds to the Previous or Next Item. Note: This will depend on how many items that exist in the Quick Access Bar