Well, nDoc has fallen behind the times, not really supporting all of .NET 2.0 yet. Namely, generics are not supported in the latest released version of nDoc.

Here are some tricks to work around it:

nDoc Wiki has some info about .NET 2.0 support, but the Wiki is down for now.
Using Google caching, I grabbed the page by searching for ".net 2.0" ndoc support then looking at the cache page.

The above wiki/cache page talks about a config file change to support 2.0. But then it goes on to link to some dude's blog where he's got a 2.0 compatible version working.

nDoc 1.3.1 v16