Recently I found that the freehub on my Hope XC rear hub won't rotate, but only when the wheel is in the bike and the quick release is tightened.
I've removed the freehub (which slides off easily), and serviced the pawls and springs.
I thought perhaps tightening the QR pushes the freehub against the lip seal, preventing it from rotating.
I spoke to Hope, who suggested that it might be that the internal spacer has worn. However, when I insert a small washer behind the spacer and install the wheel again the freehub still locks, despite there now being a visible (though small) gap between the freehub body and the lip seal.
Here's a link to the exploded diagram:
http://www.hopetech.com/webtop/modules/_repository/documents/XCRearHubExploded.pdf
The spacer I'm referring to is item number 5. The seal is item 11 - the 11 nearest the right (there are two).
The behaviour is the same with the cassette removed.