[Inkscape-user] can't delete a single knot

Hi,

I have a drawing of a hand, which I reduced to 4 colors. Each color I converted to a path. In Inkscape I have now 4 layers, on every layer one path.

A part of all that you can see here: http://hagoschaos.de/h/freunde/inkscape1.jpg

If I try to delete one single knot(for example that one, where the pointer is hinting to), quite a bunch of knots disappear(those, which describe a little color-patch with only one knot).

How can I select just a single knot, without affecting the others?

Regards, Hago