We are fully aware of that the bug is already fixed in RHEL 6.5 AMIs and that there is a workaround.
However, a customer who wants RHEL and PV AMIs has to stick with the 6.4 AMIs since 6.5 was HVM only.
This means that there is still a chance that customers can hit this bug, and we are receiving reports from paying RHEL AMI customers about it.
We would like to get the RHEL 6.4 AMIs re-spun to include this fix.