If the field is always the same field in the application, the problem is not in the alias you have but in the mapping properties that you are mapping that component. Basically, each time through the application, something is changing so that TestComplete needs to remap that component as a "new" one.
So... go take a look at the criteria that is being used to map that component, look for dynamic stuff there, possibly add some additional properties or refine the existing properties so that you will get a consistent mapping each time.
