Here is a re-post of what I found on Symbian's website. We have to wonder why Nokia claims the Symbian OS SDK IS compatable with Visual Studio .NET:
Author: Phil Spencer Date Reported: 11/03/2002
Log Number: CPP-897
Is current ER6 SDK compatible with Visual Studio .NET?
Visual Studio 6.0 (VC++ 6.0 SP3) is the only supported version of Visual Studio for Symbian OS v6.x SDKs. For ER5 you can use the older VC++ 5.0 as well.
We have no plans to support Visual Studio .NET. Any development you wish to do with the SDKs under .NET will be unsupported and cannot be guaranteed to work - lots has changed beteween VS 6.0 and .NET.