Apple ipod

I know that the Ipod is supposed to be one of the, if not the, best mp3 player today, but may I just ask....If that's supposed to be the truth, then why am I going into my 4th Ipod in the last two and a half years?

I'm walking to the train and I reach into my bag to pull out my ipod & headphones. I turn my ipod on to look for the new John Legend album that I purchased late last night(btw...I also watched it load into itunes, you can never be to sure with computer programs). As I go to search I find that ALL 7,100 songs have been removed from my ipod. My photos are still in tact, but the most important thing to me, my music, is gone. This is traumatizing...I only pray that the day gets better because that was not the way to start the morning! I wonder...If the is the way all Mac electronics work, I may have to retract the posting about the IMAC G4.