I am unable to reproduce this. I created a gateway quiz with the 4 problems in the tar ball you attached, and the same settings as in your picture. I answered all of the problems, and clicked on the preview button. The preview showed the answers I entered, and the problem parameters were still the same. If I graded the test, it all seemed to work as it should.
I tested this on a server using webwork and pg versions 2.15, as well as with the develop branch. I did have to change the © symbol in the problemPanic.pl macro to © to get quiz to load for version 2.15. That has already been done in the develop branch. However, I don't think that has anything to do with the problem here.
What version of webwork and pg are you using?