Heroku PGError bad migration cancels db:migrate

Help Please... Rails 3.1.3 ruby 1.9.3p0 Heroku --cedar

heroku run rake db:migrate causes the following error...

-- change_column_default(:users, :admin, {:default=>false}) rake aborted! An error has occurred, this and all later migrations canceled:

PGError: ERROR: invalid input syntax for type boolean: "--- :default: false " : ALTER TABLE "users" ALTER COLUMN "admin" SET DEFAULT '--- :default: false

Im sure its a SQL to posrgreSQL issue, but having the defaults set is not really imperative so decided to remove them in a migration...

I removed the defaults completely with a migration (after trying several other schema changes thru migrations to see if postgreSQL on Heroku would work).

No matter what I changed in later migrations, Heroku gives same error message.

I tried removing the text from the offending migration, saving it, and commiting the changes to Git, pushing them to Heroku, then rerunning db:migrate, but it does not effect the error msg from Heroku. Heroku seems to keep seeing the migration no matter what I do.

I guess I need to know how to clear heroku of the migration it is stuck on and then have it not get stuck on the same migration when I run rake db:migrate on heroku again...

Thanks in advance...

Third argument to change_column_default should not be a hash, probably a nil.

Peter