When working with variables and advanced actions, you need to be able to see what the values of all relevant variables are to ensure the values are what you expect. I usually set up a debugging environment in my Captivate project file so that at any point I can see what all the variable values are:
Perhaps your user variable isn't being updated or assigned as you think it is. Being able to see the variable IS or IS NOT holding the correct value will at least allow you to remove that as a possible reason why this is failing.
If the variable IS indeed correct, then the issue must be in the Advanced Action. Check that you are referencing the correct objects by name.