Version:           1.2.0 (using KDE 3.5.0 Level "a" , SUSE 10.0 UNSUPPORTED)
Compiler:          Target: i586-suse-linux
OS:                Linux (i686) release 2.6.13-15-smp

Steps to reproduce:
1. Switch on Settings > Configure KStars > Guides > Coordinate Grid
2. Change the coordinate system by View > Equatorial Coordinates and View > Horizontal Coordinates. 

Actual result:

The horizon is put on the x-axis when horizontal coordinates are selected and the equator when equatorial coordinates are selected. This is expected behaviour. 

But only RA/Dec grid is shown even when Horizontal Coordinates are selected. This is unexpected behaviour.

Expected result:

When Horizontal Coordinates are selected, the altaz grid must be shown.

Argument:
There's a difference between the viewmode and the grid that gets plotted on the map. The specified menu item toggles between equatorial and azimuthal viewmode but the grid in the map is always a RA/Dec grid.

Reply:
The menu item says "Horizontal Coordinates". It is very difficult to get an idea of the horizontal *coordinates* without an altaz grid. IMHO there is no meaning to a "view in horizontal coordinates" without an altaz grid. 

Therefore:
An altaz grid must replace the RA/Dec grid when viewing in horizontal coordinates is desired.

Alternative/additional suggestions:

1.
Instead of just a Settings > Configure KStars > Guides > Coordinate Grid setting, use three checkboxes. 

One is: "Display grid according to active coordinate system system". If this is checked, disable the following two: The second checkbox "Display RA/Dec grid" and third checkbox "Display Altaz" grid. When it is unchecked, enable individual selection. I will create an attachment illustrating this.

2.
In the View menu, list both Equatorial Coordinates and Horizontal Coordinates, and when one is selected, deselect the other. Otherwise, one has to *deduce* that the current mode is the one that is *not* listed in the View menu. Using a Radio button type selection in the View Menu clears up the situation.