Okay I thought this was my fault, but now I've seen it happening in front of my eyes: I had entered an appointment in my iPod touch. Today I looked, and it was there. Then, I connected to iTunes. Everything got synced. And behold, I return the Calendar on the iPod, and the item is GONE! It is not on the iPod nor on iCal on my Mac. This thing has happened to me several times now, and I don't feel comfortable depending on the feature anymore if events get lost.