My car was doing the same thing.
I changed plugs and it didn't help, so I used some techron, and tried gas from another station, and it seems to have subsided. I think there might be some bad gas floating around in places.
You can also look into your OVP. I did not change mine, I just kept running premium fuel form different stations until I found one that the car started operating normal on. My car has since stopped doing it.
You may just need a simple "Italian Tune-up.."
hehe
I did notice that since I decided to drive the car harder for a bit, it has been running better. it could be mine was related to some carbon build up. But any of the above mentioned stuff should give you some ideas of whatt o look for.
Alon
Post some pics of your car if you can, I want to see it.