Horizons on winex - problem with addsmooth?

This game has been working for a while now, however it still
requires a launcher writing for it (which I am working on) as
the current launcher requires MS IE.

It has a couple of issues with some of its graphics shaders
however which were causing the game to exit and dump with a
memory access violation.

These happened when using texture shaders that contained
"addsmooth"

Using the same shaders with just add rather than addsmooth
seems to have fixed the problem.

Is addsmooth supported by winex? What open GL call does it become?

Either way why would parsing a file that uses it report a
memory access violation?

I'll try looking at the source myself when I get chance, but
my knowledge of renderers is sketchy at best.

Simon