I use it for migrating my site from Joomla 1.5.22 to Joomla 2.5. But first I need to upgrade my Joomla manually from 1.5.22 -> 1.5.23 -> ... -> 1.5.26.
Ensure the setting are correct. What I've tried.
1. Skip check
2. Skip downlowd
3. Skip unpack
(I use the unpacked copy of stable Joomla 2.5 on the jupgrade folder, means I do it manually since my internet connection is not that good). Not working well on IE9 but working well on my latest Firefox.