Starting Problems
 

A few weeks ago, I parked the boxster for about an hour, came back and it cranked, but did not start. After 6 - 8 more tries, it did. The car was running fine for a couple of weeks when it stalled @ 45 mile per hour. While waiting for the tow truck for 30 minutes, it started OK. Brought it to the shop, where they thought it was the fuel pump, changed that, and all was well. On the way back home, I stopped for a haircut, came back, it wouldn't start. Came back in 3 hours, it started right to drive it back to the shop.

any advice on how to proceed?

I had a similar problem. Not sure what year your car is or whether your problem is the same as mine. Here's a link to the discussion. Crank position sensor was problem.

http://forums.pelicanparts.com/boxster-cayman-forum/598662-hot-start-problem-99-boxster.html