i'm glad you got it fixed, but you are running 3 pronged devices requring an earth into a non earthed socket ?
whatever you do, dont put two metal things powered from that, and then touch both with your bare hands
otherwise you;ll get a nice 55 VAC 15A buzz (half mains potential) .... or ground yourself and the device same thing....
try this, put the back of your hand up to the metal of the machine thats not earthed, dont touch it, just hover closley over it, you should feel a slight buzzing sensation, thats the electricty ground itself into you.
some devices are double shielded and you may not see that effect, but typically they don't require a ground..
If you want to do a much safer check get an AC voltmeter stick it on the 110V AC range and press one end to the metal of the case, then the other in your fingers..