The problem appears to be that ADE does not indents numbered lists or bulleted lists with the paragraph forced up hard left against the edge of the screen. If the numbered list includes greater numbers than 9 then only one digit is shown. I have tested the epub on other readers including: Mobipocket reader, Nook study, FBreader, Calibre reader and others and can not reproduce this problem. It appears to me that there is a serious software bug in ADE. I use Smashwords as an epub distributor and they use ADE to check the epub for faults before distrubution and my epubs are rejected even if there is nothing wrong simply because ADE doesn't display the epub correctly.
This is probably down to the defaul (agent) css used by ADE.
It is looking ok for me with lists of over 100 items (using ADE 1.7.2 because of bugs with ADE2.0).
If you make your embedded css more explicit, the result should appear more precisely the same on different devices.
I'm having the same problem as gotored, though in my case with epub files rendered on a Kobo reader.
Within the standard li/ol formatting, I don't see what I can add to resolve this.
Can you please give more detail about "making the embedded CSS more explicit", or perhaps point to where I can learn more about what's involved?