I never go anywhere afar but went to Vegas a couple months ago...we booked the whole trip on Southwest Airlines site and all went well.
Originally we tried to book with Orbitz and all we ended up with was a maxed out credit card and no trip to show for it even though I was charged for it 3 times
(long story and even an longer story to get it straigtened out...I will refrain from telling you the painful details)