Jason Jones points out that the NLB fix that applies to TMG also must be run on the UAG server if you want to enable Network Load Balancing.
You can install this fix before or after the UAG server software is installed. However, you should do it before you enable NLB on the array.
For more information on this issue, check out Jason’s blog entry at:
DEBRA LITTLEJOHN SHINDER
MVP (Enterprise Security)