Toyota - Camry :: Brakes Are Binding On Drive

I drive a 1997 Toyota Camry with 210,000 miles on it. Recently, my brakes were grinding. My ex-mechanic father said he would replace them. When he took the wheel off, he found that the calipers were bound and had been for awhile, as the rotors and pads were metal on metal (whoops). Both sides were completely replaced- pads, rotors, and calipers (he figured if one caliper was binding, the other was or could be soon, though the wear wasn't as bad). He bled the brakes and things were ok for about a month and a half.

My new issue is that the brakes are binding on my drive home from work (after it sits outside for 7-10 hours). The car lugs along. I pull over, try pumping the pedal (which is very stiff) and then make my way home, where my boyfriend takes the car around the block and does something magic and the brakes are no longer stuck. They aren't stuck the next morning, but are when I get in the car at the end of the work day. The wheel wells smell strongly of burning rubber as well.

Things we have checked : We've jacked up both front wheels and the tires spin. They spin less easily when the brake binding problem is present, but they still spin. We've checked the suction, the hoses that connect the booster to the engine, and the brake booster- all appear ok. The brake fluid levels are fine. The pedal remains stiff when you put the car in neutral and even when you turn it off. So what do I do next? We're semi-handy and I'd like to drive this car a bit longer, though I've started the replacement car search.