I had same problem.
It was .htaccess file having problem.
I saved in mode of UTF8. must be saved ASKII mode.
i changed it,add permission 666 and set on the config page of wordpress about "permanent link".
i set it "numeber" link name.(i do not know how to say cos i am using japanese version)
then front page came with like this page's URL
"http://qqqqqqqqqq.com/wordpress/lang/en/frontpage/".
I mean, saved UTF8 that is very basicaly my falt, but there is the problem around ".htaccess" flie or "permission" or "Apache configlation(AllowOverride)", could be.
---caution--------------------------------------------------------------
*wordpress can access to .htaccess file and overwrite , when you set permanent link.but if you didint add permission 666, wordpress say "you must change contents of .htaccess by your self"so, if you can change it, you should do before you do anything.