mySQL - Cannot add Foreign Key Constraint I'm trying to add a foreign key constraint but, mySQL is not taking it.  No detailed error, just Cannot add foreign key constraint

Here is my code from an export dump...
thanks for any assistance

-- create tables
CREATE TABLE `calltarget` (
  `idCallTarget` int(11) NOT NULL,
  `idImportCTBatch` int(11) NOT NULL,
  `idBroker` int(11) NOT NULL,
  `idCallMaker` int(11) NOT NULL,
  `FirstName` varchar(40) DEFAULT NULL,
  `LastName` varchar(40) DEFAULT NULL,
  `StreetAddress` varchar(60) DEFAULT NULL,
  `City` varchar(30) DEFAULT NULL,
  `Province` varchar(10) DEFAULT NULL,
  `PostalCode` varchar(7) DEFAULT NULL,
  `MobilePhone` varchar(13) DEFAULT NULL,
  `HomePhone` varchar(13) DEFAULT NULL,
  `Email` varchar(80) DEFAULT NULL,
  `Broker` varchar(80) DEFAULT NULL,
  `Carrier` varchar(60) DEFAULT NULL,
  `Notes` varchar(250) DEFAULT NULL,
  `Status` int(11) DEFAULT NULL,
  `CUser` int(11) DEFAULT NULL,
  `Created` datetime DEFAULT NULL,
  `MUser` int(11) DEFAULT NULL,
  `Modified` datetime DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;


...

CREATE TABLE `importctbatch` (
  `idImportCTBatch` int(11) NOT NULL,
  `idBroker` int(11) NOT NULL,
  `idCallMaker` int(11) DEFAULT NULL,
  `ImpFileName` varchar(80) DEFAULT NULL,
  `ImpDate` datetime DEFAULT NULL,
  `ImpStep` int(11) DEFAULT '0',
  `Created` datetime DEFAULT NULL,
  `CUser` int(11) DEFAULT NULL,
  `Modified` datetime DEFAULT NULL,
  `MUser` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;


-- add primary keys
ALTER TABLE `calltarget`
  ADD PRIMARY KEY (`idCallTarget`);

ALTER TABLE `importctbatch`
  ADD PRIMARY KEY (`idImportCTBatch`);


-- set autoincrement  
ALTER TABLE `importctbatch`
  MODIFY `idImportCTBatch` int(11) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=8;

ALTER TABLE `calltarget`
  MODIFY `idCallTarget` int(11) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=182;

-- restrict deletion of importctbatch when calltarget records exist
ALTER TABLE importctbatch ADD 
CONSTRAINT `fk_importctbatch_calltarget_idImportCTBatch`
     FOREIGN KEY (`idImportCTBatch`)
     REFERENCES `calltarget` (`idImportCTBatch`)
     ON DELETE RESTRICT;
I think you've got the FK the wrong way round, and really want:

ALTER TABLE  calltarget ADD 
CONSTRAINT `fk_importctbatch_calltarget_idImportCTBatch` 
FOREIGN KEY (`idImportCTBatch`) 
REFERENCES `importctbatch` (`idImportCTBatch`) 
ON DELETE RESTRICT;