Tranny won't come out of gear?

[roccit_53 at scirocco.cs.uoguelph.ca (C Boyko)]

The boy's shuffling his cars around, and is trying to get his Rabbit
project to roll by putting it in neutral (on the tranny). It makes a light
clicking noise when he tries to shift it, but not the normal click you'd
hear when it engages. When he jacls it up, the wheels turn (in opposite
directions) even when he applies a bit of resistance to one of them, which
he's taking to mean it's still in gear. Suggestions?