Hi today i had the same problem like you - flash eMMC stop on 20%. what help me was write in this topic http://talk.maemo.org/showthread.php?t=66004&page=3

post from J4ZZ (thank you J4ZZ) what i do: 1)flash PR1,3 than 2)flash PR1,2 than 3)try flash eMMC it still stoped on 20% but i can boot to maemo now. I use win7.

Next problem was with site when i booted to maemo i can´t join to mobile site(operator) so i try update maemo to pr1.3 by wifi it doesn´t help so i did again flash to pr 1,2 and everything is ok now. Everythings work like on the new phone.
Try it - it helped me, maybe it will help to you too. Good luck.
P.S. srry for bad english