Yeah - and, as a hiring manager, when I get a glowing endorsement of: "yeah - he worked here from 2006 to 2008." I treat that as a big warning.
The OP's concerns are valid. He wants positive reviews and NOT the "worked here" review.
And yeah - sue them. Employees that sue their employers, even when right, have trouble getting hired again. So if you sue your employer it had better be for something serious enough that you are either 1) making the world a better place by eliminating a gross employer abuse 2) getting a LOT of money such that you won't need another job.