I know this is a Fusion Hybrid specific board but I though I'd throw this out there in case it helps any other Fusion owners.

My parents and a close friend both bought I-4 2010 Fusions during August. Both have mentioned, and I have on one occasion witnessed, the car will sometimes turn over (starter engaged) but will not start. In all cases trying to start a second time (Key OFF/Key ON/Start) will result in the car starting up.

I researched the issue today and located a TSB regarding the issue. I don't have access to the actual TSB language (maybe someone else on here does) but here is what I do have:

TSB 09-19-1 - 2.5L ENGINE - INTERMITTENT HARD START / LONG CRANK - WITH ONE TOUCH INTEGRATED SYSTEM (OTIS)

Details:
"As a result of the previous post about our 2010 I-4s sometimes continuing to crank W/O starting, (2010 4 cly. keeps turning over), I spoke with my service manager at Ford. There is a TSB (technical service bulletin) out on this problem. It is TSB 09-19-1. Apparently there is a ground strap near the engine that is causing the problem. They replace it with an up-dated version and that is supposed to eliminate the no start issue. Mine is on order. This is warranty work and therefore it is of no cost to the owner. Just call your dealer, refer them to the TSB number, they will order the part, and install it under warranty. It doesn't take long ( 0.4 hr.) and you could probably wait while they install it. The reason for the no start issue is a little technical, but suffice it to say that the new grounding strap is supposed to eliminate the issue. Hope this settles this concern. "
ref: http://www.fordfusionforum.com/index.php?showtopic=2522