using negative coordinates doesn't change the fact that menubar is over the gemwin.... [menubar 0( remove the dock, but not the menu bar (on the top...)
I don't know if someone tell you a solution.
On a Mac mini Intel/Pd.0.42.5.extended, I did it with this message, connected to gemwin :
[reset, border 0, menubar 0, dimen 1600 900, offset 0 -51< | | [gemwin]
Note : the "dimen" arguments must be your screen size.
Jerome