I see no difference in the 2 you have.

It might be because your cookies in your browser is not updating. I use to have that problem, but the real difference between the "www" and with out the 'www' is that one means world wide web for NO cookies storage on the users computer. You should always use www if you're planning to use any other sub-domains and you want them cookie-free.The other means its cookies are stored on the users computer. KEEP IN MIND: Internet Explorer is known for doing this, firefox does not do this.

If you are on apache server, (which you are), you can take advantage of the .htaccess file in the root of your home directory. You can force "www" into your site address if you like, but personally i rather promote my domain name with out the extra "www" in the name.

I think it's the setting of the server your site is on. But here at Voda host you will not have that problem.

hope this was helpful.