LyX ⇒ Problem with sequence of objects in beamer slides

[lyxer]

Hello,

I've been trying to fix a problem with the sequence of objects in beamer slides but with no luck.
I'm attaching a sample file to describe the situation.

In frame 1, and after the second bullet, I have to click twice before I can have the content of the
column environment to appear. Why does that happen?

In frame 2, I would like to show the Definition first, then the Example, and after that the content of
the column environment, and finally the sentence that reads "Final Conclusions". I tried using overlay
specifications and the visible property but it didn't work. So, what I have now is that when I first enter the frame, the Definition, Example, and last sentence appear at the same time.

Appreciate any help with this issue.

SAS