I have the same problem, so I deleted all the passwords and data and now some won't save again. I have the autocomplete on extension but it still doesn't work. The form has autocomplete on but no save password option once logged in.
1. Upgrade to latest version - auto fill of username and password stops working on some sites. Also saving passwords stops working on some sites.
2. IE9 can save the password where iron cannot, but iron cannot then import that either.
I found a copy of the old version and that is not working either.
I installed iron on another machine and that is the same both before I synced and afterwards.
Firefox is looking quite appealing!