Endpoint Encryption

I am currently using SEEDC v8 and am having a problem.

I've RTFM and can't seem to find the solution to it. 

We are currently trying to allow the USB drives tgat were issued by our dept and block all others.  We have them allowed by placing the manufacturer and model numbers in the storage device white list. and no others.  It seemed to have been working but we are running into an issue where a number of outside USB drives are getting allowed even though they should have been explicitly dis-allowed. 

We DO have the unclassified devices blocked as well to no avail.

What am I missing here?

...that these outside USB drives that are getting 'allowed' are of the same make/model as the ones issued by your department?

I'd suggest running the DC Auditor on a machine that allowed the outside USB drive, and checking if the device details match those in your whitelist as a first step.