it all started when itunes told me to upgrade to the 9.0 version. I did that, and once i was on 9.0 the itunes store would not work because it needed the newer version of safari. I tried to download it, but my computer is not new enough for it or something therefor i could not upgrade the safari. SO, i then decided i wanted itunes 8.0 back. At first i thought i could just redownload it, which did not work. I then read that the 9.0 has to be uninstalled before i could downgrade. I did that, and when i downloaded 8.0, none of my music was in there... i got frustrated and redownloaded the 9.0, in hopes of my music being back. Well, it wasn't. It gets much worse. All of a sudden everytime i would try to open an application, it said that there is not enough memory. my mac has never said that before, and i know that the memory was fine. i can't drag any items, no pictures from sites onto my desktop. I cannot drag anything, it just wont move. i can't upload ANTHING due to the "zero mb" which is not true, and when it tells me to delete things to bring back mb, nothing changes. i cannot upload anything such as pictures from my digi camera, my firefox also got effected, the back button simply does not work. I can't "copy paste" anything since it won't paste when i press it. I can't even transfer any of the data on this mac to my new mac. It doesnt let me burn anything to a disk, i can't open important applications, i can't save anything what so ever. i can't take things out of trash bin due to the dragging option not working. This all started after i downloaded itunes 9.0 and then tried to bring it back to 8.0. PLEASE if anyone knows what the hell im talking about i am desperate to know what is going on here and how to fix it! THANK YOU!