Visual Studio 2003 is not fully supported on Windows Vista (look at the know issues there)
Visual Studio .NET 2003 on Windows Vista Issue List
and read this
Visual Studio on Windows Vista FAQ
For developers using Visual Studio 2005 on Windows Vista, Microsoft is in current development on an update to Service Pack 1 called the ‘Visual Studio 2005 SP1 Vista Refresh Beta’. This update builds on the improvements made in SP1 and delivers a first class experience for developers wanting to take advantages of the new features in Windows Vista. The Visual Studio 2005 SP1 Update for Windows Vista is expected to ship after the consumer availability of Windows Vista in Q1 of 2007 and is now available in beta
http://www.microsoft.com/downloads/d...c-5863284503cf