Then another problem,after I unregistered cgi-2006.9.6,the fastcgi-2006.10.9could't work well with cgi-1.0 .
You might need fastcgi-1.0: http://www.cs.chalmers.se/~bringert/darcs/haskell-fastcgi
Actually,I was trying my best to install hope: http://www.cs.chalmers.se/~bringert/darcs/hope and lasted for three days, it's really too hard.
Would I be right to think that your problems are not specifically related to the cgi/fastcgi/hope code-base, but more general problems diagnosing package version conflicts? The Haskell community has been working hard to improve various aspects of the user experience. Perhaps if you describe the kinds of issues you had (and any solutions you've found), others on the list might be motivated to provide a better experience for future users.