Hmm... I wasn't watching very closely, but for me the light would come on and be gone within a day or 2. Then later that day or the next it would come back on.
It stayed on even after I fixed my cap. And even came on briefly after filling my tank (for 3 miles or so).
I'm no mechanic, but I'd recommend you make an appointment to have it checked out, and if the issue resolves itself before the appointment than just cancel it.