I have noticed two usibility problems. All "problems" relating to a completely new project. I use Windows XP SP3.
Click on 'Layer 0' -> Rename the layer with F2 -> press the 'Del' button.
Hmm strange the tooltip says to me: "This is the last layer..." I just want change the layer name not deleting it <img src="smileys/smiley5.gif" border="0" align="middle" />
Also press several times the 'Del' button and look at the shadow (come to the dark side... <img src="smileys/smiley4.gif" border="0" align="middle" />) from the tooltip. Looks like many tooltips overlapping.
2) New layer
-> Create a new layer (Layer 1)
-> Right click on a layer (toolbar is context-based and show correct settings)
-> Now right click on the white listbox (toolbar is furthermore context-based and shows you only the button 'Add layer at top')
-> If the context menu is opened, click on the selected layer
-> Context menu lost context-based informations
Puh I hope it's understandable ^^