I may be a little off topic here but here goes.

I'm having an issue with my fascia/soffit getting moldy and rotting.  There is no apparent roof leak to account for this.
I live in a hot humid climate (FL).  There are no soffit vents or ridge vent, only a gable end vent. 

There has been a lot of talk here about air movement in attics and under roof decks so I thought someone might be able to shed some light on why this is happening.  I suspect air movement might be the cause but I'm not sure how that all works.   

Not really clear on why this is happening at all and especially why it is happening at the soffit area.

Thanks in advance.

bman;

you may be getting some siphoning along the eave ( running back up) it would cause the water damage along the facia and soffit, without leaking in the house itself.
I don't think its an air flow problem

This sounds right.  See if the roofer remembered the drip edge.  As silly as it sounds I've seen it forgotten.  Also if it does have a drip edge it's important that the end it hanging in the air.

had a roof recently where the shingle installers had not offset the gaps in the starter course to the gaps in the first row of shingles. Worth checking into.