ERROR 1005 (HY000): Can't create table 'phact_greenland.cache' (errno: 121)
You get Error 121 when you try to create a table that contains a constraint with the same name as a constraint defined elsewhere in your database. You can avoid this issue by naming the constraints yourself in the creation script. More information can be found below:

InnoDb Error Codes

http://dev.mysql.com/doc/refman/5.5/en/innodb-error-codes.html

Create Table Statement

http://dev.mysql.com/doc/refman/5.5/en/create-table.html

I hope this helps you.