Merge Clips desync my clips

Hi! I am new here. I am from Argentina. 

So... I have a problem.

I sync my audio and video like this:

Is well, but not to well. It doesn't matter. The sync is right. The problem comes when i make a Merge Clip with this (i need it, because i work with several sequences of syncing, and i don't want to go to that sequences when i need something).

When I make the Merge and paste it in a sequence (i choose the same sequence in this case) it comes like this:

See? It's desync... I don't know why. I checked all the settings of the sequence and clips, it's ok. I am not editing alone, I have a partner who edits in his own computer, and he has the same problem. In fact he told me what is happening.

So... Any guesses?

Sorry for my bad english. Thank you a lot!