Using Multiply for distorting uvs does not work as expected - breaks shader when nodes are connected.

I have included the screenshot that works:

and then one that doesn't

and the flurry of errors that this connection produces. 

If I want to re-connect the "working" network, the shader will no longer compile, and has to be thrown out.  I'm happy to learn the "proper" way to achieve this, but this method seems intuitive.  Can you reproduce this?