Version of magento commerce is 1.9.1. It is not even working when i didn't install the one step checkout. I tried after disabling the one step ...
enter image description here. Did you check the url that is coming on button? Seems you might have changed the default action on the button.
Try loading the address directly from the customer/address model. I have edited your code. I have also indented and formatted your code.
Solved! Magento was lazy with their changelog and lazy with not updating their magento-check.php file. 1.9.1.0 requires that your server has php-mbscript ...
Change the script in lotusbreath/onestepcheckout/onepage/review/info.phtml to: