Move layer moves wrong layer

Hi

Used to have PS 14 but now upgraded to PS 18 (both for Mac).

In previous version, when selecting a layer in the panel, I could place the cursor anywhere in the canvas and drag the layer as I wanted.

With this "new" version, this has become a nightmare. Every time I select a layer in the panel to move, some other layer will be affected. I need to re-select umpteen times and really make sure that I click some actual content pixels in the layer to make it move. (Hope I managed to explain...)

This drives me bonkers and I've been trying to find some setting that stops this from happening. How can I (by default) make layers I select in the layer panel STAY selected when I want to move them?

Cheers,
Dani