I just replaced my original powerbook hard drive with a 160 gb WD scorpio and it's make a clicking sound occasionally (like every 10 seconds maybe...) I've heard clicking can bee a failing hard drive but i don't know if it's this kind of clicking... It's not in a rhythmic pattern or anything, just the occasional click. could this be because it's a bigger hard drive? i feel like this hd is generally louder (although not by much) than the one that apple gave me, which sorta sucks becase wd claimed it was the quietest 2.5" drive. obviously not. i might just be paranoid, but wanted to get some of your expert opinions on this. thanks everyone!!