iPod: 2 months later

So I had put off actually getting an iPod despite pretty much all of humanity owning one, and raving about its greatness. I was late on jumping on the cell phone trend also, just because of my general apathy towards new technology. This past birthday, however I got an iPod nano (which I filled up in a day, and then exchanged for the video iPod). My main hesitation, aside from money wasted on something that will play music I can easily play on other mediums, was my own anal-retentive nature to keep the songs organized and labeled. Big surprise, I have to have all my tracks labeled and numbered properly. The only real advantage is that if I download something I only have on vinyl, I can put it on here and listen to it in more places. It's also nice that I can play it in my car, so I don't have to make mix tapes anymore. I also use it while at work, so I don't have to bring different CDs in every day. I have no interest in downloading from the iTunes music store, or putting pictures or videos on it, nor would I say I'm obsessed with it. I doubt I'd even recommend getting it to anyone.
Anyway, all was fine I suppose until this Monday. I rip my CDs on my work computer (Mac), and download stuff I have on vinyl from my home computer (PC). I never had any problems going cross-platform before, since I have this Mac reader program on my PC. On my way to work Monday I was listening to the new songs I loaded on there over the weekend, but when I plugged it into my computer at work the songs didn't play anymore. In fact all the songs I had loaded in the past from my home computer stopped working. It's like they moved directory and iTunes couldn't find them. I obviously didn't change their directory, since I have no idea how to. So now I have to delete and re-upload all the songs from my home computer, which is a colossal waste of time. Way to go Apple... You've got a great product on your hands that forgets how to play half my songs after 2 months.