BTW - I made the change locally, and ran into one more issue. The
CodeBase property of the assembly returns the full path in the form of
a file uri("file:///", for example). The Path.GetDirectoryName method
fails on receiving this text.

So the proper code should look something like this:

Uri uri = Assembly.GetExecutingAssembly().CodeBase;
...Path.Combine( Path.GetDirectoryName( uri.AbsolutePath ) ,
"ccnet.*.plugin.dll" )

I apologize for the ellipses; trying to recall the code off the top of
my head.