Calling .NET code from IronPython, getting error while loading log4net assembly

I have an IronPython script that configures log4net and then calls .NET code that uses log4net. log4net is configured correctly as I am logging a message to indicate that it has been initialized. But when I try to use my .NET class it says "could not load file or assembly log4net, ...".

Some useful facts:

• log4net is not installed in the GAC
• .NET class is correct, I named it from other .NET code
• the log4net assembly loaded in the PGM is in the same folder as my .NET assembly.
• filemon shows that all access to log4net.dll has been successfully resolved from the expected location
• fuslogvw doesn't report any binding errors
• I add both log4net reference and .NET assembly references using AddReferenceToFileAndPath ()

What's strange is that the log4net build is already loaded. It has to load the .NET assembly into a different AppDomain. If so how it works it would be good to know.

Any ideas? Thank.