Getting ec2 instance ID suddenly stopped working

I've been getting an amazon instance ID from within the instance itself for over a year now by hitting this local web address http://169.254.169.254/latest/meta-data/instance-id. This is the appropriate method according to the AWS documentation. For some reason though, just this week that same call started throwing an error.

I tried pinging the 169.254.169.254 address from the command line and that fails, so it seems like something pretty basic has changed with the EC2 instances. I don't see any changes to the documentation on AWS. One thing I do notice is that I used to see the instance name in the upper right hand corner when loading up the instance and logging in remotely. That information doesn't appear anymore.

Here is the code I've been using to get the ID:

retID = New StreamReader(HttpWebRequest.Create("http://169.254.169.254/latest/meta-data/instance-id").GetResponse().GetResponseStream()).ReadToEnd()

Here is the full error stack:

   at System.Net.HttpWebRequest.GetResponse()

   at RunControllerInterface.NewRunControlCommunicate.getInstanceIDFromAmazon() 

The error message itself says: Unable to connect to the remote server

Any help would be appreciated.