In my passport, my name is Firstname middlename1 middlename2 lastname, and in the ticket is LASTNAME/FIRSTNAME MR.
Will be a problem? I'll travel from Brazil to Bali, Indonesia and according to the agency I bought the ticket from, there's no problem and it's common.
The airline is Qatar Airlines and I have looked this link, which says that the passenger name can't be changed after the booking has finished.
But I don't know if it is a problem.