SheepishOne

Weird. I always thought this was from the Ewok Adventures movie, where the little girl is explaining what a star cruiser is to the little Ewok. She zips her hands around and says zoom! So the Ewok picks up a wooden pony and goes ZOOM ZOOM, STAHCROOSAH! Hence. Space ponies.

Is it possible you were upgrading your fleet number while queuing more ships? This was the only time I've gotten a negative amount, but it was soon rectified by the upgrade's completion.