Please either enable error displaying in osTicket or consult your PHP error logs. If you are getting a blank screen then its highly likely that there is an error being thrown.
You can turn errors on in OSTicket by editing the /main.inc.php
Locate:
#Don't display errors
ini_set('display_errors',0);
ini_set('display_startup_errors',0);
and change it to:
#Don't display errors
ini_set('display_errors',1);
ini_set('display_startup_errors',1);
Let us know what your seeing for errors. (Also make sure that you go back in and shut it back off later!)
You should also start your own thread in the 1.7 section of the forums not zombie a thread from 10/2012.