>As for the comment made about breadboards being the worst way to
>go... keep in mind I'm just testing it now, I don't plan on boxing
>this up and using it with a breadboard :-)

I suspect the problem is the breadboard. This is allowing all sorts of
horrible lead lengths at places they should not be, which is allowing the
switchmode chip to oscillate in all sorts of uncontrolled ways, and this is
what has destroyed your chips.

The only way you are going to sort this is to go straight to a PCB which has
been laid out with current paths and suitable sized tracks straight off.
Then you will get something that will approach the stability you require.

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