Thanks GJP, that's interesting - it sounds like it's possible there could have been real weather reasons for the cancellation of the later flight, in the afternoon.
Although, the reason might be slightly different: yes, there is another runway (the main one), which is 06/24. This one has lighting, but 17/35 does't, as far as I know.
There was already a couple of hours delay on the flight at the point it was cancelled - it's conceivable they were looking at the METAR showing the 150 degree wind. I'm speculating they might have gone past the point they could land on runway 17, since I assume it can only be used in daylight.
Cheers
Brutha