excessive exhaust when starting engine

[ranbar2]

I know that some white smoke from the exhaust is normal for boxsters that have sat for a while (a day or two or longer), but I seem to be getting excessive exhaust every time I start the car. I had my 30K service last month and the car got a clean bill of heath. I didn't really notice the smoke until I stated the engine while in a parking garage last week. I almost asphixiated the couple that was strolling behind the car. The car seems to be running as well as it always has. So I am wondering what is the "normal" amount and frequency of smoke on start from a boxster and if this is something I really need to be concerned about.