This was really aggravating. I booked a US Helicopter flight on Thursday from JRB - EWR via Continental.com for a departure leaving later that day (they hadn't bothered to remove the flights from the computer system).
I had a 45 minute connection to my EWR Continental flight (booked in first) to DFW. When I got to the heliport (luckily well in advance of my flight) they told me all flights had been canceled that day due to "heavy maintenance." I wasn't offered any assistance or advice as to how to get to Newark on time to make my flight. For anyone familiar with the area, it isn't exactly the easiest place to hail a taxi, particularly at rush hour.
Luckily, I managed to snag a cab after walking several blocks with my bags... then told the driver to step on it to Newark... I was one of the last to board, making my flight just before the doors closed.