This is a message I received after I ran check db in phpMyAdmin:

Problems with indexes of table `table_xoops_banner`
PRIMARY and INDEX keys should not both be set for column `bid`

Problems with indexes of table `table_xoops_bb_posts`
More than one INDEX key was created for column `topic_id`

Problems with indexes of table `table_xoops_bb_topics`
PRIMARY and INDEX keys should not both be set for column `topic_id`

Problems with indexes of table `table_xoops_newblocks`
More than one INDEX key was created for column `mid`

Problems with indexes of table `table_xoops_priv_msgs`
PRIMARY and INDEX keys should not both be set for column `msg_id`

More than one INDEX key was created for column `to_userid`
Problems with indexes of table `table_xoops_ranks`

More than one INDEX key was created for column `rank_min`
Problems with indexes of table `table_xoops_users`

PRIMARY and INDEX keys should not both be set for column `uid`
More than one INDEX key was created for column `uname`

Problems with indexes of table `table_xoops_wfschannel`
PRIMARY and INDEX keys should not both be set for column `CID`

Problems with indexes of table `table_xoops_xoopspoll_log`
More than one INDEX key was created for column `poll_id`