This has happened to me on a number of occasions, especially when I've bought tickets in eastern Europe. Quite often they translate your name into cyrillic and then back to latin when the ticket is printed, the result being that your name is spelled very differently to what appears on your passport, for example the name Steven becomes Stiv. Never had a problem though.
Also, every ticket I've ever bought has displayed the abbreviated format of my first name whilst my passport displays the full version. Again, never had a problem.