Are there other controls on the panel? If so, in the tab order, is the grid the first control?
Are their other controls besides the panel on the form? If so, is the panel first in the tab order?
Is column 1 or row 1 of the grid hidden? The default behavior is to set cell 1,1 active, and if it is hidden you will not see it.
You can try explicitly setting a current cell, but I suspect the problem is some kind of tab order/active control problem that will have to be resolved by some other means.
//in form load...
grid.ForceCurrentCellMoveTo = true;
grid.CurrentCell.MoveTo(1,1);
You might also try setting this.ActiveControl = grid to see if that affects anything.
Here is a sample of a grid in a panel on a form with readonly cells that seems to come up OK for me. Does it for you?
WindowsApplication10-1_3118.zip