In our organization we use log4net for all our .NET 1.1 applications. For our new projects we use Visual Studio 2005. At this moment there is no public version that supports the .NET 2.0 framework.
In the log4net mailing list people claim you can use the current version but this is only partially true:
It’s true, for application running with trust level full,
but it’s false, for all other trust levels.
When the trust level is set to something other then “Full” a Security Exception will be thrown.

If you want to build a secure ASP.NET Application you do not want your application running with full trust.