Got a new hard drive for my Inspiron 1545 - an SSD, at last! Turns out it was probably just in time too, as I found an unrecoverable bad block on the WD it is replacing.
Just one problem. The SSD is smaller than the drive it is replacing. Not narrower (they're both 2.5" drives - which means they're both 2.75" wide). But thinner. I suppose that dimension isn't standardized by anybody. But surely that can't actually be a problem? After all, thinner still fits in the drive bay...
Guess it is a problem after all. Near as I can tell, the SATA port in the Inspiron requires the drive to completely fill the bay in order to force the all the contacts to ... contact.
Good thing the problem is that it's too thin, not too thick. I can fix this.
Thanks for the well-engineered hardware, guys.