You haven't really said... have you connected it to the RC Assistant utility? Not just the Vision Assistant, but the RC Assistant?
Also... are we talking about rechargeable batteries? Because, depending on the cell technology, they may not be packed fully charged... and may have lost charge on the shelf. You'll want to make sure they're charged. And even if they're typical non-rechargeable alkalines, you'll still want to test the voltage to make sure they have a charge. Don't just assume that since they're new, they're good.
And if that still doesn't work, check the voltage. If they're 1.2v, you might just try some 1.5's.