Cannot connect over USB to AD9915

I am using two of the AD9915 devices in a single setup and am unable to connect to either over USB to the computer that has been integrated into the setup. However, it is possible to connect to both on an alternative computer (one that cannot be integrated but is available for testing). I have checked the obvious issues, i.e. USB connections, and attempted a software reinstall with the setup files from the working computer but these have not been successful. Has anybody had a similar issue before?