No boot condition after upgrade to 10.8.3, EFI 1.6, Mid-2009 15" MBP 2.53Ghz

Hi,

I've got a Mid-2009 15" MBP. After I upgraded to 10.8.3, my computer got into a situation where, upon waking from sleep, it became unresponsive, and then gave me the "no entry" sign after I hard-rebooted it.

I took the drive out, put it in an external enclosure, found that it booted via USB. I then put the drive back in the computer and to my surprise, it booted and worked properly -- for about a week, at which time the problem recurred.

Some more detail: a while back I upgraded the HDD to a Seagate Momentus 7200 750GB, model ST9750420AS. I encountered poor performance, spinning beach balls, refusal to wake from hibernate, etc. I came upon the EFI 1.6 monster thread (https://discussions.apple.com/thread/2054387) and downgraded my EFI to 1.6 and kept it there. Everything worked great for more than a year, until the 10.8.3 update and no boot.

It looks like some people who downgraded to 1.6 are having issues with 10.8.3 as well, but with an HDD/SSD in the optical drive (https://discussions.apple.com/thread/4895074). I can confirm I'm having issues with it when the optical drive is intact and I'm using a SATA HDD in the HDD bay. This is a supported configuration (my owner's manual even has instructions for upgrading the HDD).

The second time it happened I tried what the folks in the second thread above did and downgraded to 10.8.0, then upgraded to 10.8.2. I can say that at this time it seems to be working. So my questions are:

1) Is 10.8.2 the last Lion update this MBP will ever be able to install?

2) Has anyone who was previously running EFI 1.6 / 10.8.2 had this issue and had success with the 10.8.3 / EFI 1.7 combination (upgrading both at the same time)?

3) Has Apple or anyone else found a definitive list of HDD/SSDs that work reliably with this rather finicky logic board/disk controller?

4) Anyone else running EFI 1.6 / 10.8.3 having a similar experience? Should I be worried about the longevity/integrity of my hardware at this point?

Thanks. Please chime in especially if you have a similar configuration/experience.

Alex