I've an iPod touch 16GB firmware version 3.1.2. I let it sync with my iMac (2006 white plastic) running Mac OS X 10.4.11. I've just upgraded my iTunes form 9.01 to 9.02, and my iMac does not recognize iPod touch when I plug-in the USB connector. I can't see iPod touch in the iTunes, and the iPod touch does not even show the charging screen.
Then I tried to connect iPod touch to my MacBookPro 13" 2009 running Mac OS X 10.6.2 and iTunes 9.0.2, and it works just what it should be.
Does iTunes 9.0.2 incompatible with Mac OS X 10.4.11 ?
I'll try to do some self-cleaning tasks and try it again.