Dual head setup, how can I use only extruder two? BUG?

Vertex 3D Printer Vertex - Printer software (repetier, slicer, ...)
1

Hi, the repetier software refuses to use the second extruder if there are no objects that require the first extruder.

So I can use the second extruder, on condition that there are also objects in first extruder colour.

Practical: I cannot print a single object with the second extruder, even when I select ‘extR2’ in the object three before slicing.

What am I missing or is this a bug?

2

Same problem here. I can only use the second extruder when I use both of them. Must be a bug.

3

To use the second extruder you must use the “Single head” Print Configuration in the Slicer tab and select EXTR 2 for your object in the Object Placement tab.

4

Here’s the solution, it works:
viewtopic.php?f=61&t=14620

edit: indeed, Raby’s solution; thanx Raby