Very weird..This link seems to be a bit spotty..
It also might be a translation...note the grammatical errors.
Here is the question/answer:
Question:why the area can be used will be decreasing after upgrade the A730 ROM to version 3.43.02.7?
the theory[don't public]：
Answer:We implement a 96DPI mode in V3027, which is a real VGA mode.
But we do not release the switch mode tool to user yet.
The 2 MB is used for this new feature.
the referrence for reply:
As the ROM version is upgraded, the function of PDA will be better, and the area for need will be more.
We suggest you to upgrade your PDA, and you will take a better function.
If you want to restore the ROM as factory default, you can go to the repair center. Our professional engineer can help you to restore it.