We continue to experience increased API error rates for the EC2 APIs in the AP-SOUTHEAST-2 Region. We have confirmed the root cause, and are working on multiple paths toward recovering the subsytem that is impaired, which is responsible for networking related API calls. This issue mainly affects EC2 RunInstance, and VPC related API requests. Customers using the EC2 Management Console may experience errors Describing Resources, as well as making mutating API requests. Connectivity to existing instances in the AP-SOUTHEAST-2 remains unaffected.

from Amazon Web Services Service Status: http://status.aws.amazon.com/