Problems with importing slides from other presentations - new slide layouts

Usually when one imports slides from another presentation there are no major difficulties, the slide adopts the destination format automatically and all is well.

Here's a sample of a perfectly integrated slide, the title slide that is inserted follows the destination formatting:

But sometimes things seem to go wrong. Here's a sample of a slide that does not follow the destination formatting:

Seems like the Title layout of the destination presentation has totally been neglected.

Worse, PPT has added a totally new Title slide layout to the existing ones.

What could cause this to happen. Well in this case it is quite simple the source presentation has a Title slide layout where one of the placeholders (subtitle placeholder) has been removed from its master.
So if you want to avoid trouble it is a good idea to not remove placeholders on original slide layouts.

To solve our problem we will have to apply the correct Title slide layout from the destination presentation to the imported slide, then we can remove the extra slide layout from the master. If there is a slide using a slide layout it can not be removed from the master.