Ex-'Housewives' Star Aviva Drescher -- Makes Promises Hollower Than Her Left Leg ... Ex-Manager Claims

Fired 'Housewives' star Aviva Drescher got paid $100K to star on another reality show ... then screwed over the manager who got her the gig -- at least that's how the pissed off manager sees it.

The ex-manager claims she booked Drescher and her husband, Reid, on "Marriage Bootcamp" and says the Dreschers promised her a 10% commission -- which amounted to $10K.

In a lawsuit, the ex-manager says Drescher slandered her in interviews ... by calling her "sleazy" and a "wannabe agent."

The ex-manager says she only got $2,500 of her commission, so she is suing for the balance ... and for damages to her reputation. We tried contacting the Dreschers ... but no response so far.

Tip for the ex-manager -- beware of flying limbs.