I was having this problem of not being able to migrate my ratings. This is what worked for me, your mileage may vary... I had a laptop, XP and WMP10, with a USB portable hard drive that contained all of my media. I spent the time to rate about 80% of my songs. I enabled the setting, Maintain my star ratings as global ratings in the media files located in the tools, options menu, under the library tab. I then selected the Process Media Information Now located in the tools menu. After that I disconnected my USB drive and pluged it into my new media center 2005 PC. I imported all of my files and none of my star ratings where there. After some digging around and letting it fester for a couple of days. I noticed that on my MCE PC I did not have the Maintain my star ratings as global ratings in the media files enabled. I proceded to enable this settings and I received a message box that warned me if I click ok it will import my ratings from my files and overwrite what is in the media library, click cancel if you don't want to do this. Well, of course I wanted to because I was migrating. I clicked okay and after a few minutes my ratings appeared. Problem solved... Well, I hope this helps atleast one person out there. It seems you can run the process multiple times by disabling clicking apply and then reanabling. I suggest that if your media library is more current than you files in terms of star rating that you use the Process Media Information Now and then redo your import.
