Currently Being ModeratedNov 9, 2012 1:34 AM (in response to mirbeau)
First, spinning hard drives don't use TRIM, so you can't enable it on your HD, only your SSD.
Is your SSD your boot drive? Where do you have your iTunes media stored? There's a right way and a wrong way to change the location of the media - see http://support.apple.com/kb/ht1449.
Currently Being ModeratedNov 9, 2012 2:22 AM (in response to clintonfrombirmingham)
Thanks! I just needed to select the "keep your library organized" option.