Alright I converted my IPB to MyBB and not only did all of the posts containt smilies get messed up but...users can't login even after asking for a new password! Not even I could ask for a new password! until I changed the loggin key. Also, about 60 members were automatically moved into the moderators group and I didn't have any back then. Is there a way to mass move them into the regular members group? Prob. through cpanel? Also, this password thing really sucks, could I fix it? I have a backup of the original passwords from a backup I did from my IPB forums.
For your usergroup problem, you could mass move everyone in the moderator group to the member group by running these queries:
UPDATE mybb_users SET usergroup = 2 WHERE usergroup = 6;
UPDATE mybb_users SET displaygroup = 2 WHERE displaygroup = 6;
UPDATE mybb_users SET additionalgroups = 2 WHERE additionalgroups = 6;
(Make sure the table prefix is accurate, of course.)
As far as the password issue, I'm really not sure how to fix it. The DB obviously didn't handle the passwords well. One thing I might think of off the bat is that you were running an incorrect IPB version for the convertor you used, but that probably isn't the case. Perhaps simply re-doing the whole conversion would prove useful?
The converter cannot automatically convert passwords from IPB to MyBB due to the different ways that the password is encrypted. You'll have to ask all your users to request their passwords, or find a script that can automatically regenerate new random passwords for everyone.