I have a customer that I will be upgrading from VM only 2.4(6.135) to 2.4(6.161). The CCO docs I have found say that you need to be at NT4 SP6a and Exchange 5.5 SP4, not to mention the various hot fixes. Are there later NT4 and Exchange 5.5 SP levels that are recommended or is the CCO documentation accurate? Thanks in advance.