Hello Guys,
After many trials, I figured out my problem...
First, like Zewall above, I tried everything you guys suggested, still did not work...
The problem was in my icloud sync process!
I mean, I’ve rebooted the iphone back to original factory many times, but I always synched to my icloud just afterwards to get all my contacts and apps.
After I was trying to add the music in all possible ways, no success, the damm dotted circle was there and no songs from the library was loaded to the iphone.
Just by mistake, this last time I did not logged in with icloud in the rebooting process of the iphone, and thus no apps nor contacts were synched with my icloud account, so the iphone was just like new!
I tried now to synch the songs and WORKED !!!
The songs from the library was loaded to the iphone!!!
Well, I had to add my contacts again, had to download all the apps one by one again..
But at the end solved my problem!!!