Emacs locks when entering an nnrss group

Emacs locks when entering an nnrss group

[Evans Winner]

I have several groups defined by nnrss.  When I'm in the
*Group* buffer and hit enter on one to go into it, there is
always a message that says:

Generating summary...done

And then Emacs hangs there until I hit C-g.  Once I do that,
then I can manually switch buffers to the summary buffer it
has created.  I don't really know how to begin
troubleshooting this.  Is it something someone already knows
about off-hand?

Thanks.