Scaling down recipes with BeerSmith - Experiences?

I plan on scaling-down 5 gallon extract with special grain recipes to 2.5 gallon batches to help some friends get over their fear of homebrewing.  Plus, it will allow me to experiment with some beer ideas that are a bit more out of the mainstream.

According to BeerSmith 2, halving the extracts and grains seems to give the target OG and SRM.  But halving the hops is giving me higher IBUs.  I thought that smaller volume boils (I'll do the full volume boil of 3 gallons or so to account for boil-off) resulted in hop under-utilization, so I was expecting lower than target IBUs.

What do you think of this?  Also, any experiences with scaling-down and what might have to be tweaked in BeerSmith?

No idea, sounds odd. I would just halve everything and ignore Beersmith.

I do exactly the same thing.  I like lots of smaller batches, more variety and I''m the only drinker untill my kids come home from college, then I'll have to scale up

Anyway I did a scale down by half for a recipe and the hop bill went from 1.8 oz to 220 oz.

I think there is a bug here somewhere