Inaccessible devices

[meguiraun]

in /usr/lib/python2.7/site-packages/svgsynoptic2/taurusregistry.py trying to add listener to an inaccessible device crashes during the _update method. So, the listeners to the next attributes will not be created.
Adding:

except TypeError as e:
    print "Failed to setup listener for", attr, e

here, helps at least on the subscription for the next devices.

PS: the exception I was getting: cannot create weak reference to 'NoneType' object