Originally Posted by HarryT
I don't think it's that so much as the fact they're now using a better MobiPocket creation tool.
Baen are much the same; their older Mobi books with a ".prc" extension are rather primitive and lack navigation links, etc. Their more modern Mobi books (with a ".mobi" extension) have proper cover images, working nav links, etc.
There may be another difference. In Palm based products there is typically a limit to images of 64K bytes and in MobiPocket devices that are not running on Palms the images can be larger. The limit of 64K may no longer be true of Palm's either but was true in the recent past.