Well I was able to resolve my problem (which may be similar to yours).
I received my MacBook Pro 13" yesterday, along with 4 GB of memory from NewEgg. I had a spare WD 320 GB sitting on my desk, and figured I would throw it in the MacBook instead of shelling out more cash for a 500 GB.
So after I install everything, I put the ten screws back in the MBP, connect the power supply and try booting.
Nothing!
Just a gray screen and nothing more. I was immediately a little put off, since I had just returned a DOA White MacBook the week before. I perused Apple's Support site and tried a number of things. Lo and Behold the good ol' Command + Option + P +R PRAM zap did the trick. After the second chime and restart the MBP came to life.
Amazingly, the 320 GB drive held an image of 10.5 off of my iMac 2.8 - and it still booted to it without an issue. I was kind of surprised. I played around in 10.5 a little and debated sticking with 10.5 or installing 10.6 that came with the MBP. I decided to do a clean re-install so that I could play around with Snow Leopard (I was holding off from installing it on my iMac until I was completely satisfied with its stability, like after 10.6.2).
I erased the 320 GB drive and did a clean install of Snow Leopard. Installed iLife and all the other apps I needed. I was feeling pretty good and really was impressed by the little 2.26's performance with 4 GB, even when running VMs in VMware Fusion. Feeling proud of myself I shutdown the MacBook and took a break.
Upon returning, when booting up I was met with the same gray screen that I had originally been confronted with. WTF! I went from being pretty happy to deflated quickly. I got it booted up again by resetting the PRAM. It took me about 45 minutes to realize that the MBP would boot nicely, every time, if it were restarted. The issue was only when I shut it completely down and then tried booting up again.
I ran the Hardware Diagnostics and it came back good. I figured if the hardware passed it must be software and had to be fixable. Apple's Support site, at this point, recommended re-installing the original Apple components, but I really didn't want to have to pull the memory and hard drive out, and reinstall the original hardware. I created another Snow Leopard Boot drive off of an 80 GB USB drive I had. I booted into it, from a complete shutdown, without issue! I felt like I was onto something... From the USB boot drive I tried repairing the internal 320 GB drive - which didn't fix the problem.
I went back and read through the MacBook Pro EFI 1.7 Problem thread (which really needs to be stickied) found here:
https://forums.macrumors.com/threads/729883/
I downloaded EFI 1.6 and followed the directions on pages 12 and 13 of the thread. Used a USB 8 GB stick to install the EFI 1.6 Firmware, and booted off of it.
Bingo - solved the problem. I can boot from a complete shutdown in less than 30 seconds now (timed from pressing the power button to having the login screen shown). I was amazed that it worked, and was pretty angry at Apple for not correcting such a widespread and easy to resolve issue.
So now, my only issue is having to remember to tell the updater not to install the 1.7 update. Besides that I am very happy with my now zippy and stable MacBook Pro 13"
Hope this might help! And I thank everyone who has contributed to the EFI 1.7 Problem thread (and especially for hosting the EFI 1.6 update on Rapid Share) - you guys saved me from tearing my hair out! MacRumors.com rules!