>When enter is pressed in the next to last column, the grid shows empty whitespace to the right (sort of an empty column) and hides column one.
>
>This is confusing and annoying - so how can this behaviour be suppressed?

I've solved it this way. At the end of grid's (class level) .init I'm setting the width of the last column to just fit:

n=0
FOR i=1 to this.ColumnCount-1
	n = n + this.Columns[i].width
endfor
* bittest is there in case we don't have a vertical scrollbar
this.Columns[this.columncount].width=this.width-n   ;
   -iif(bittest(this.ScrollBars,1),Sysmetric(5)+this.ColumnCount,0)-4

The sysmetric() call gives the width of the vertical scrollbar. And 4 is the rule-of-thumb amount for the grid's own border, padding etc whatever it may have.