2003 Nissan Altima rough start?

I have a 2003 Nissan Altima 2.5, 100K miles. After driving for a while i park the car, 10 minutes later i start the car and it idles rough for a few seconds, like its not getting air or gas then everything is fine.(couple of times it didnt even start). Idles around 700rpm in Park and 600rpm in Drive. I have new spark plugs and and cleaned the throttle body. I also took it in for the recall of reprograming the ecm. Also have a coolant leak, but mechanic couldnt find a leak and he said its not going into the engine. I lose an inch of coolant from reservoir every few days. Its been like this last 10k miles.