If you are using InterAction 5.5 SP2, you have probably run into limitations relating to Office 2007, Vista, and even 64-bit application servers.  All these items are fixed with InterAction 5.5 SP3.  The Outlook Plug-in has been updated to match the look and feel of Office 2007, providing a much more user-friendly interface when deployed with the newest version of the Office Suite.  Additionally, search capabilities have been improved which will help companies with large numbers of opportunities and engagements lessen the time it takes for users to get the information they need.  As always, the new service pack is available for download from support.interaction.com.