Old Type d question

[Ikaruga102]

I've been playing around with my type d from puzzle pros for a bit but then all of a sudden I realize a cap for corner piece was missing. The other corner pieces don't have a removable cap.

Is it suppose to be like this?

 

[abr71310]

Wow, what the heck? It must have fallen out on a random solve; my YUGA does this a lot too.

Hmm, they're all removable, as far as I know, they just don't LOOK removable unless you somehow bent in a piece and saw how the seams don't EXACTLY align.

 

[mcciff2112]

My white YUGA does the same thing too. I had to put some sticky tack on some of the caps because they fell off so often. They were interfering with my solves.