Steps to reproduce:

According to the ** Update operations of an Action are supposed to fire when a problem is:

1. 
   commented upon
2. 
   acknowledged
3. 
   severity changed
4. 
   closed (manually)

However when I try this The Update operations never fire. If I manually close the problem the Recovery operations fire, but even if I acknowledge the problem, any of the macros (e.g. {USER.FULLNAME}, {ACK.DATE}, ...) are not replaced.

I have attached  a screenshot of my Update operation and the text from the Problem and Recovery emails that I received.