Will migration assistant import my previous boot ROM version?

Hi. I've been reading these forums for a long time...first time posting.

I have a MacBook 5,2. It came with OS X 10.5. As far as I know, the latest boot ROM for 10.5 on a Macbook 5,2 is MB52.0088.B05 (EFI 1.4) (see http://support.apple.com/kb/HT1237).

A while ago, a friend convinced me to update to 10.6. Apparently, with the 10.6 install, it updated the boot ROM version to MB52.0088.B06. Now, I'm concerned that there is a firmware issue (which I might be wrong about, and the reason I think there is a firmware problem is very convoluted but I'll explain if you want). So I decided I wanted to go back to MB52.0088.B05. I had been thinking about going back to OS X 10.5 anyway. So, I backed up my system using Time Machine to a Time Capsule via ethernet. Then I did an Erase and Install with the original 10.5 install disc that came with my Macbook. Then, I used Migration Assistant to restore most of my system from the backup. I should have taken a look at the boot ROM version before I ran Migration Assistant...but I didnt.

The boot ROM version still says MB52.0088.B06.

I tried downloading the MB52.0088.B05 update and running it anyway, and it says my computer doesn't need the update. When I was still running 10.6, I did try the method described here: http://pubmem.wordpress.com/2011/04/09/flash-efi-firmware-update-manually-on-a-m acbook-51/ (which has apparently worked for someone else on a 5,2; see https://discussions.apple.com/thread/3747472?start=0&tstart=0), and it didn't work. I don't know if it's a good idea to try it again now.

So:

Why didn't my boot ROM go back to MB52.0088.B05 after a clean 10.5 install?

Did Migration Assistant import the previous boot ROM somehow?

Should I do another clean install without MA?

Should I try PubMem's manual method again?

Is there another way I can flack back the firmware?

Thanks a ton!

P.S. I posted this in the MacBook community as well. Don't get mad, I'm new. If that's against the rules, I'll take this one down.

Specs:

Model Name: MacBook

Model Identifier: MacBook5,2

Processor Name: Intel Core 2 Duo

Processor Speed: 2.13 GHz

Number Of Processors: 1

Total Number Of Cores: 2

L2 Cache: 3 MB

Memory: 2 GB

Bus Speed: 1.07 GHz

Boot ROM Version: MB52.0088.B06

SMC Version (system): 1.38f5

System Version: Mac OS X 10.5.8 (9L31a)

Kernel Version: Darwin 9.8.0