As genixia pointed out, from

Checking for extra DRAM:
c0c00000: wrote ffffffff, read ef1ba9f0

it seems it is not properly recognizing the 12MB-16MB block. I'm thinking there are a few possibilities:

- The installed memory was bad to begin with. Hugo, who sent Stu the chips to install, mentioned somewhere that they had a high fail rate. I'm not sure if they were tested pre-install.

- Something might have gone wrong with the install. It was the first (only?) Mk2 upgrade that Stu had done. He posted a pic here, and more details are scattered about that lengthy thread.

- I don't remember reading about any other Mk2 memory upgrade successes, so maybe there is something else that still needs to be worked out for Mk2s specifically in Hijack. I know it's a long shot, but it's what I'm hoping for given the alternative of being out my player for a week or two with the shipping turnaround to Stu.

If anyone has any other ideas, I'd appreciate it...