Bug#586324: Printing fails with "/usr/lib/cups/backend/socket failed" fixed for me

[Esther de Rooij <esther@lisannederooij.nl>]

I had the same problem with a permission denied for the backend, after I 
upgraded my cups
to version 1.4.3-1

After some searching on the Internet I found debian bug number #585153, 
which describes more or less the same
problem.

The solution for that problem (chmod go+rx /usr/lib/cups/backend) also 
fixed my problem. I'm almost sure it will also
fix your problem.

See the bug #585153 for more details.