Your API key looks a bit short...
Did you just register your API key? According to Eugene O'Neill on this forum:
After registering an API key and specifying a valid domain, it may take up to 30 minutes for the changes to take affect, so if it doesn't work immediately, go grab a coffee and check back in a few.
Also, make sure you specified your API Domain.
He outlines the full series of steps as follows:
To register an API key:
head over to https://www.linkedin.com/secure/developer
log in and click the link to Add New Application
fill out the following info:
Company (choose from the dropdown)
Application Name (e.g. My Company Jobs)
Description (e.g. For receiving applications from job applicants)
JavaScript API Domain (this is an important step. this is the website the button will go on e.g. http://www.mycompany.com)
Application Use (select one from the list, if nothing matches your needs, choose "other")
Developer Contact Email (your email address)
Phone (a phone number you can be reached at if there are issues with the account)
check "I agree" Security text (enter the characters you see just above it)