(I have got ClassPad OS version 1.24 and ClassPad Manager version 1.00)
If for exmaple we take Keppler's Third Law, we have an equation as below:

everything is fine, but when we change "r" into "a" we get:

It's the same in the ClassPad as in the ClassPad Manager.

(the 1 and 2 in index forms are taken from the soft-keyboard abc | math )