gd-png error: setjmp returns error condition 2

I'm using ImageCreateFromPngPtr() on data that is apparently incomplete,
i.e. not a valid PNG, and I'm getting the error as in the subject. 
My own code handles the problem on my end, but after a couple of more
times with the same problem (in the same process), I get a segfault. 
I'm running on ia32, I'm using libgd 2.0.35 and the latest libpng.  I
have not yet totally isolated and reproduced the problem, but I'm
working on it - does anyone have any pointers in the meantime?


thanks
/Per Jessen, Zürich