There is a common issue that when you setup your own domain name with blogger, none WWW URLs are not getting redirected to your blog address and it just show 404 error.
In order to over come issue, you need to follow given steps.
Log-in to your domain manager and add A records for following IPs
216.239.32.21
216.239.34.21
216.239.36.21
216.239.38.21