Delicious API is broken today Jan 30, 2013. It looks like the “New Delicious” update messed up with ability to post links through the API.
There are many reports on Twitter confirming that outage is general:
We are monitoring the situation, but can’t do anything about that at this point.
Just purchased your script and noticed this, d’oh.
Please keep an eye on this for us 🙂
Sucks that half the things you can supposedly do with your plugin – you CAN’T. Funny – your accounts all seem to work fine??