Errors [42S01][1050] and [HY000][1025] when trying to add foreign key to table in MySQL

I am trying to add a foreign key to an existing table like this...

alter table expeditedaddress add foreign key
        FK_ExpeditedAddress_Brokerage_ID(brokerageId) references brokerage(id);

And get the following error

[2011-10-05 14:54:28] [42S01][1050] Ta开发者_JAVA技巧ble '.\realtorprint_dev\expeditedaddress' already exists
[2011-10-05 14:54:28] [HY000][1025] Error on rename of '.\realtorprint_dev\#sql-20a4_17' to '.\realtorprint_dev\expeditedaddress' (errno: -1)
[2011-10-05 14:54:28] [42S01][1050] Table '.\realtorprint_dev\expeditedaddress' already exists

For clarity's sake her is the show create table for the two tables which are involved...

CREATE TABLE `brokerage` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) CHARACTER SET latin1 NOT NULL,
  `agency_id` bigint(20) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `idx_Brokerage_agency_id` (`agency_id`),
  CONSTRAINT `FK_Brokerage_agency_id` FOREIGN KEY (`agency_id`) REFERENCES `agency` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=17 DEFAULT CHARSET=utf8;

CREATE TABLE `expeditedaddress` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `description` varchar(255) CHARACTER SET latin1 NOT NULL,
  `address` varchar(255) CHARACTER SET latin1 NOT NULL,
  `city` varchar(255) CHARACTER SET latin1 NOT NULL,
  `country` varchar(255) CHARACTER SET latin1 NOT NULL,
  `stateProvince` varchar(255) CHARACTER SET latin1 NOT NULL,
  `zipPostal` varchar(255) CHARACTER SET latin1 NOT NULL,
  `brokerageId` bigint(20) NOT NULL,
  `timezoneCode` varchar(100) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `country` (`country`,`stateProvince`),
  CONSTRAINT `ExpeditedAddress_ibfk_1` FOREIGN KEY (`country`, `stateProvince`) REFERENCES `stateprovince` (`countryName`, `name`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;