Startup of 64-bit instances flaky?

I'm making a stab in the dark here implying that it's an issue with the 64-bit servers, but I've had problems deploying applications on both high-mem and high-cpu instances. Two week ago, the problem was having my Elastic IP automatically attach to the server. This week, not only that, but apache doesn't start. (I have to ssh into the server and manually do both as part of my deploy procedures to the High CPU instance.)

Any ideas?

Early in the morning. Clearly it's not the AMI image that's the problem, I have the same application running on a few "large" instances that use the same AMI. Yet, I've never had a problem with those. Same AMI, identical WARs, same topology. The only deltas I have are: 1) The server instance is High-CPU, not Large; 2) My EBS for the DB is much larger (500MB)