As you crank up the power on a telescope, it's the exit pupil (the size of the circle exiting the eyepiece) that shrinks and makes it more difficult to find the image. Scopes tend to work best when the exit pupil is somewhere close to the diameter of the human eye's pupil (about 3mm depending on light conditions). You can calculate the exit pupil by dividing the size of the objective (probably 50 or 60mm) by the magnification.
If by chance your scope has a removable eyepiece (which it likely doesn't), you can try substituting an eyepiece with a longer eye relief. A set of fixed power eyepieces will probably give you a better image than a variable power eyepiece.
Orion Telescopes (www.telescope.com
) is a good source for spotting scopes and eyepieces that are better than your run-of-the-mill department store scopes.