I had the same problem. I am not sure how my tables got corrupt but I lost "params" and "activation" columns in addition to having to reset the auto-increment in the extra field.

I suspect my issue was caused with using both the joomla and CB login forms. I had to track down other notes to identify the conflict of the two mods running simultaniously.

Thanks for your posts... the bread crums lead me to fix my issues...

CN

wel simple explanation
add 2 new field

params and activation and it will work