Hi,
Welcome to flyertalk and the BA forum pitspeedbird

It is not only IAD that is affected by the A380 delays
The reliability of the A380 fleet since they have come out of storage has not been the best according to reports . I think a couple might be in maintenance.. That and the current usage pattern of the fleet ( with no spares) results that if one aircraft develops a fault it can have a knock on effect througout the A380 fleet network.
I'm sure someone with more technical knowlege will be along later.
If you are affected by the delay you may be able to claim compensation
Regards
TBS