Uninstalled plugins are listed in plugin settings after upgrade

[Cyanide_]

A list of plugins that I used to have installed before the the upgrade from 1.6 to 1.8 are still listed under plugin settings. I have verified that the files do not exist within ftp. 

Any ideas?

Thanks!

[Devilshakerz]

Settings and setting groups can be removed manually in ACP's Configuration → Settings →Modify Settings (you might want to create a database backup before that operation).