Thanks for posting that.

I don't really understand what you meant buy "If Google changes your page title...". How do they change the title? They display something other than the original title?

Yes.  They are changing the display title.  If you read the post and look at the images you'll see that two of Meg's results show different titles for the SAME page.

Ok, now I see.  Indeed, those should be in the keywords meta field.

Now what about the same title in many pages? I use that in my Page of the Month. Each entry in my PotM has as a title "P�gina do M�s - Page of the Month" plus the specific title. that is "P�gina do M�s - Page of the Month -:- Lambda Centauri". Is that wrong?

I would say it would be worth a test, at least.  Google a couple of your posts by specific names (in quotes) and see if it keeps your title or changes it.  Google your site name, too.  You'll know if they like it.

As far as what I think will happen - I think if the majority of the FIRST 70 characters are the same, you'll be penalized. Maybe put the specific title at the beginning?  That may overcome it - hard to say without testing. As I said, this is all new so we're trying to figure it out.