Many owners of the MacBook Pro mid-2009, sporting the EFI 1.7 are experiencing problems (here for a summary). With a variable frequency, the laptop will freeze for couple of seconds to one minute, similarly to a HD failure. Several hypotheses have been proposed, without much success, and many users are expecting an EFI update to fix the issue.
Well, it seems that we will still have to wait for a longer time as a reliable source told us that there is no one defined to work on this issue at Apple, and there is no EFI 1.8 update planned for the moment. So most users will be left with 2 options: keep using the EFI 1.7 with a compatible HD (as some model are not compatible), or downgrade to the previous version 1.6 with a limited SATA transfer speed of 150 MB/s. To make things even easier, APR can not perform this backward operation, only Genius from a physical Apple store can do it.
If you do not like those 2 options, there is a third one, known as "Aluminum_MacBook_Pro_Recovery.dmg" t hat can be found on internet. You will of course act on your own and be responsible for all potential side effects.
There is still a bit of hope as not all HD are generating such compatibility issue with the EFI 1.7, and maybe HD manufacturers will take it into account and will offer a firmware update. This would particularly be true for SSD manufacturers as they consider the Mac market as a steady and fast growing one
