This is a nasty problem that I had with my domain http://www.freecallshub.com. I have a blogger account and I hosted my blog at GoDaddy.com. I tried forwarding my domain using Godaddy's forwarding option but it will work only for few hours and then again it will stop working. I finally found a way to make it work.
The issue with this is that you need to tell Google that you want to forward your domain without www. This way the nameservers get updated and that way you can forward your domain.com to www.domain.com without any issue. To do this follow these steps.
1. Login to your blogger account
2. Go to Publishing under settings.
3. You will see a checkbox under your domain name which says forward your domain to www.domain as shown in picture below.
4. Check that box and save your settings.
It will take some time to update your name servers. Once they are updated you will be able to go to your website without typing www. This is the easiest way to do it.
If you do not see this option please switch to blogger domain and then publish it to custom domain again. Post comments if you can not get this working. I will put up a video tutorial on how to do this.