Hi, all. I'm super new to inkscape, I want to use this SVG: http://www.openclipart.org/detail/14335 and cut the waves out of it, so I can put some other colors to the boat and the waves.

What I'm trying to do is to select two nodes of the path and press Shift+B to cut between these two nodes, But then the image/path gets distorted (see attachment).

So my question is: How do I cut a path without distorting it?

Welcome tzicatl!

Hhhhmmm....it's hard to tell exactly what's going on there. The wave you're working on looks like it might either be a spiro spline or a calligraphic line. Please select it, then look at the info area (bottom of Inkscape window, in the middle) to learn what it is. (And then let us know.) Also, if you could give us a screen shot while the node tool is activated. Then we can see the nodes, and have a better idea how to suggest you proceed.

All this image is a traced bitmap from open clipart library, so the entire image is one path...

The first thing to note is that the image has a black fill with no stroke. When you break apart the selected nodes, the fill alogarythem has to fill each subpath sepratly - which may not be how you wanted it filled.
The simplest method around this is to
1) work in outline mode View->Display mode -> Outline
2) when you come to break the path into sub-paths, remember to join each section back up together- for example, make sure each wave is a complete sub-path so the stoke goes all the way around
3)back to view->normal
4) After you do this you will have to make the boat a different object from the waves. Select your path, go path->break apart.( This will make the entire object look black and a mess...) Then deselect the waves / select all the sub-paths that made up the boat portion of the image) and go path->combine.

Now you should have a boat object, and several wave objects

Oooooh!!
I assumed coming from Open Clipart Library, that it was an original vector/SVG.

Off topic:
Well, seeing as anyone is free to upload clipart to OCAL, it is not surprising that clipart is of different quality. The other thing to note is that a fair proportion of the images come from other public domain sources originally, and then converted into svg ( I would say at least 10% of all the images). The thinking goes that there are thousands of public domain images hidden in old books on sites like project Gutenberg that are very well drawn, and would make perfect items of clipart if in a more easy to use format.

hmmm...interesting...
Thanks tomh