using ClassDep to reduce rt.jar

[Voltaic]

i have been trying to use the JINI tool ClassDep to create a list of the
dependencies of a program i have written, but have been unsuccessful. when
i run it i output a list of classes that ClassDeps says my program needs,
but when i create an rt.jar file containing only those classes (yes, in the
appropriate package directories) i get the following:
NoClassDefFoundError: java.lang.ArrayStoreException.

i figured maybe it was a fluke, and just manually included the class.
after doing so i got the following, more confusing error:
error: java.lang.Error: java.io.UnsupportedEncodingException: Cp1252

Cp1252 is not something i specifically make reference to in my program, and
have only a nebulous idea of what it even is/does.

anyway, though, that's beside the point: i would really like to make a
slimmed down version of rt.jar to fit my specific needs according to the
classes that are needed by my app.

is there any way to do this that works, or am i just using ClassDep
incorrectly?

Please Help!
Thank You!
-Voltaic