We have made some fixes to Call Center page after release 3.0 has been issued:
- fixed order error 'MySQL Error: Column 'goods_taxable' cannot be null';
- added showing Shipping methods after selecting customer from Select Customer page.
 
Please download updated version of the files from here
http://www.viart.com/downloads/admin_order_call-3.0.zip
Then extract file 'admin_order_call.php' into the root folder of your shop and file 'admin_order_call.html' into the folder 'templates/admin' replacing existing ones.