Why won't iTunes sync my Playlists anymore?
I've been an iPhone user for a couple years now. I have the iPhone 4... iOS is up to date, iTunes is up to date. I used to keep/sync my iTunes library on a PC, but I recently purchased a Mac Pro, and I wanted to transfer everything over. All of the media is now on the Mac. When I tried to import my library, however, it didn't keep any of the "Rating" or "Checkbox" information. No problem, I went through and re-rated everything, checked all that I wanted to be on the phone and un-checked everything I didn't want on the phone. So my library is back to where it was before I changed computers...
But there's a new problem now... All of my playlists came over when I imported my library. On the computer, when I look at each one, it shows the appropriate songs I have added, either recently or over time. However, when I sync my phone, only a fraction of the songs, if any at all, actually appear on the playlist on my phone. Even if I look at the playlist in the "Devices" section where my iPhone is listed, every song appears as it should be. But on the phone itself, nothing. Some playlists have a few of the songs, but most playlists just show nothing at all. The kicker is that all the music is actually on the phone... I can access it through the "Songs" tab in the Music App on the device, but through the playlists, no luck.
I've scoured the discussions for a fix to this issue. Perhaps I'm looking in the wrong place, or I'm entering bad search terms, but I can't find anything. These are not Smart Playlists. They're just regular, Dumb Playlists. I've tried checking and un-checking various settings and applying them to my sync. My next step would be to restore the phone, but given the nature of the issues, I doubt that will work.
Does anyone have any clue why this is happening and/or how to fix it? I thought that transferring my library to a Mac computer would make this process easier and more efficient, but ever since I made the transfer, I've have nothing but problems.
Mac Pro, Mac OS X (10.7.2)