This is the right response :
rjk : Do you also use Windows 7 ? Which browser ?
Ciyam : which browser do you use ?
If you want to try another solution, you can use directly a DNS server supporting .bit
like 22.214.171.124. (Here is how to change your dns server : http://wiki.opennicproject.org/ConfiguringYourComputer
[doesn't seem to have instructions for windows 7, only for XP...] )
You can also use : http://dot-bit.org/How_To_Browse_Bit_Domains#List_of_Web_proxies
People reported it working under windows XP, several Linux, Iphone, with firefox, chrome and safari. Maybe windows 7 is the black sheep...
People reported it not working if your DNS provider respond fake replies to non-existent domains (also know as dns redirector). Are you concerned by that ?
I use Windows 7, and I tested with both Internet Explorer and Pale Moon (a Firefox variant).
I use 126.96.36.199 and 188.8.131.52, which do not hijack DNS requests. I am guessing that Windows 7 is indeed a black sheep there, and after some searching I found that you may need to edit a group policy for it to work right. Here is a pic of how I did it:
Note that it still doesn't work for me, but I may need to reboot (haven't yet). You may also need to modify the next policy down (Connection Specific DNS Suffix) to Enabled as well, and specify namecoin-suffix.dot-bit.org.
Inspiration from here: http://superuser.com/questions/71853/windows-7-not-appending-connection-specific-dns-suffix