I have installed GHC-7.0.1 from http://www.haskell.org/ghc/dist/7.0.1/ghc-7.0.1-i386-unknown-linux.tar.bz2 and installed it with 'configure' and 'sudo make install'. I get:

$ ls -l /usr/local/share/doc/ghc/html/libraries/
drwx------  3 root root   4096 2011-02-26 20:23 array-0.3.0.2
drwx------  3 root root  16384 2011-02-26 20:22 base-4.3.0.0
drwxr-xr-x  3 root root   4096 2011-02-26 20:23 bin-package-db-0.0.0.0
drwx------  3 root root   4096 2011-02-26 20:23 bytestring-0.9.1.8
drwx------  3 root root  12288 2011-02-26 20:23 Cabal-1.10.0.0
...

$ ls -l /usr/local/share/doc/ghc/html/
drwxr-xr-x  2 root root 4096 2011-02-26 20:24 Cabal
drwxr-xr-x  2 root root 4096 2011-02-26 20:24 haddock
drwx------  4 root root 4096 2011-02-26 19:31 html
-rw-r--r--  1 root root 1557 2011-02-26 20:24 index.html
drwxr-xr-x 66 root root 4096 2011-02-26 20:24 libraries
drwxr-xr-x  2 root root 4096 2011-02-26 20:24 users_guide

That is, the library documentation directories and /usr/local/share/doc/ghc/html/html/ have not enough permissions set for user access.