Hi,
there are many bugs in the types in the Pascal interface (all the range from harmless to unportable to fatal). (I don't know what happened to them, since in an old version of grx.pas I got from somewhere, GrPattern was already correctly declared as a variant record, and in grx-2.4.6 it's wrong again ...)
The attached patch should fix them, but I didn't test it extensively. So if someone else could have at look at them, I'd appreciate this.
Frank