This bug has been reported in the EC2 Forums for months now, but seems to be unreported as a bug. CRITICAL for all Windows AMI. Although valid cert keys for launching AMIs can be generated, the cert keys are reported invalid when used to retrieve the Windows Admin Password which is required to initiate an RDP session. As noted, these same keys can be used to successfully connect using the AWS Web Console.
As long as this bug is unaddressed, Elasticfox is UNUSABLE when launching Windows AMIs.
Currently using Elasticfox 1.0 build 000107 (EC2 API 2009-03-01)
Vista x86 SP2