Even though the CUPS documentation says that CUPS is accepting print jobs from everybody by default – in reality this is not the case. For your CUPS server to accept print jobs from remote hosts edit this section:
<Location />
Order Deny,Allow
Deny From All
Allow From 127.0.0.1
</Location>
by adding another Allow From option or by modifying the existing one. Again, make sure that a local firewall is not preventing your computer from receiving print jobs.