I just uploaded the Beo5 with the Windows Media Center Remote Control IR codes and it works properly as long as I push diferent buttons. When I push the same button more than once it does not work (only first time pushed). The button will work again if I push another button in between. I corroborate that Beo5 is sending ir codes if pushing the button more than once, so I guess it something related to a termination code or something like that (just guessing).

Any thoughts?

Well, I found the root cause of the problem:

The MCE Remote uses a "toggle key" algorithm when sending IR commands which means that each time you press the SAME key a different command is sent via the remote.

While this is not an issue if you use the MCE Remote and Receiver, replacing either component can cause problems. 

For example, teaching the MCE commands to a universal remote control is impossible unless the unit supports this feature.  Also if you use a different receiver or blaster, then again it must be able to handle toggle keys otherwise you must press each key twice for a learned command to be recognised.  Some receivers (such as IRMan) are not compatible at all with the MCE Remote as they produce the same code for multiple buttons

So now I need to find out if it is possible to teach the Beo5 how to use 2 different IR codes for the same button alternativelly.