You’re right, but don’t be so surprised. I can “prove” a loss on the back of a bar napkin.

Let’s assume the BO gross is roughly correct (a big assumption seeing as it doesn’t hurt the studios to inflate the BO grosses as they are often used as marketing ploys)

$56m – Gross
Less taxes and theatres’ cut (can be between 40% – 60%)

Left with $25m
Less Distrubtor’s cut (can vary but lets asume 20%)

Left with $20m
Less marketing costs (not cheap and typically at least the original cost of the movie)

Left with -$10m

Also to be taken from any profit made will be Sales Agent’s cut (if applicable), studio overhead (if not part of the $30m), etc, etc.

BUT!

You wisely brought up DVD sales. This is likely to be where the studio re-couped. Also, I’m sure I saw some related toys, etc.

In the long-run they are very unlikely to have lost money but that doesn’t necessarily make the claim completely untrue – it could have lost money right now.

Hollywood accounting is incredible – in almost any other business it’s actually called fraud but in Hollywood it’s fine.

Oh, and don’t forget to consider the validity of your sources

DreamWorks reported a $25-million loss

I don’t know how much marketing costs, but I’d be surprised if it fully accounted for the discrepancy.