It's not a problem in the theme and you could find better answer's on Q2A's official Q&A site. however here is how you can fix it:
first upload ".htaccess" file located inside Q2A's source code into your Q2A's root directory. this file allows pretty permalinks. if the problem was not resolved ask your hosting company to install "mod_rewrite" module on your server.
If your only problem comes from answer links(ending with something like #a123) or comment links(ending with something like #c123) then it's most likely a plugin error which causes it and it would be better to find the responsible plugin by removing each plugin temporarily and testing the site; then contacting the plugin's developer with this issue's detail.