2.0 framework being evil?

My boss has the 2.0 framework and 1.1 framework installed on his machine, and my developer machine has only the 1.1 framework installed. I have a project written in C# in Visual Studio 2003 (not using unsafe code), and it always runs fine on my machine, but it keeps getting System.NullReferenceException errors on my boss's machine at random intervals. Is the 2.0 framework trying to run 1.1 MSIL and failing at it? Has anyone else experienced this yet?