Please Help! Hard Drive Does Not Slide Back In!!

Hi there,

After much troubleshooting, I've come to the semi-conclusion that my upgraded 2-year old hard drive (Hitachi Travelstar) has failed. Luckily - I have been keeping a cloned external drive that is the same exact size as my internal one. However - after I tried to slide back in the backup drive, it wouldn't go in. There seemed to be a block and I tried nudging it all sorts of ways. I thought perhaps there was something slightly different in the design of the newer drive (WD Scorpio Black) preventing it from easing back in. So I put my old drive back into the bracket with the intent of booting from the original external. But when I tried to put that in - it didn't go either!

Does anyone know if something inside the hard drive slot may have moved or is being blocked? When I push the drive in, the resistance is kind of soft, like it's nudging up against rubber. I tried looking in there w/ a flashlight, but it's hard to tell. I replaced the original hard drive - so I've done this before and didn't have any resistance whatsoever then. I've tried nudging it around. And I've checked several times (looking at photos, instruction pdfs, videos etc) to check that I'm inserting it back in the right way (exposed circuit board side face into bracket w/ label showing - face down on insertion).

Maybe I'm missing something or doing something wrong that I'm not catching, but if someone can please help me - it's greatly appreciated. I'm at a loss.

I have a late 2006 white Macbook, running Leopard.

Many many thanks!