I am trying to install a 200mb hitachi replacement HD in my Macbook (black). Everything seemed to go smoothly until I tried to put the new drive into the bay. It wouldn't slide in smoothly. I saw that there was what looked to be a black piece of tape in the way. I tried to grab it and move it aside, and it dropped out. Turned out it was a sticky black rubber 'rail' or protective strip of some kind with obvious forming done to it, like its supposed to mesh with metal parts. I couldn't put it back in at this point and tried again - only to find a second rubber rail like the first still in my way. It too dropped out, clearing the way for me to get the drive in place. So now I am restoring my cloned drive onto this, and hoping everything is going to work out fine. Should I be worried about these two rubber strips, or should I take this thing back to Apple and ask them to put them back in place? I presume that my own attempt to replace the hd should not voice my warranty (I do have applecare for it). Can anyone who knows what these strips are for offer any advice as to how critical they are? Electrical isolation? To make a more stable and snug fit? thanks!