Responding to myself.
Two things i changed and system works:
By default, ez offers corporate_admin for admin pages, i replaced it with corporateadmin.
Another thing, site.ini has Database setting as "nextgen", i changed it immediately to my db name. Now it is working ok. (using wizard for install)
To test if it is the sample problem I was having, try submitting the contact form on the corporate template. In my case, the result was blank (should show a copy of the submitted info).
The problem for me was in the .htaccess file.
If you have one installed, remove it and see if that helps.