Getting the 'joining ways' function to work in Potlatch

I can’t get the ‘joining ways’ function to work in Potlatch and have been fiddling with it for quite a while and am stumped as to what I’m doing wrong. The instructions at http://wiki.openstreetmap.org/index.php/Potlatch/Primer#Splitting_ways.2C_merging_ways.2C_and_junctions say

To merge two ways into one:

* Draw your way as normal.
* When you move your mouse over another way, the points light up blue.
* Shift-click the blue point at the start or end of the other way.
* Or: if the ways are already drawn, select one, then hold Shift and click the other. 

I draw my way as normal but when I move my mouse over another way the points do not light up blue or, better, they lit up blue a couple of times but most of the time they don’t.

Does anyone else have this problem ?

Paddy

P.S. I’ve finally found the answer but couldn’t find out how to delete this post. If the ways are already drawn one has to select one then hold Shift and hold down the left mouse key while dragging over to the other way and then click on the other way. I find this a little non-intuitive but that’s the way it works for me and I profited from the neuronal workout.