I discovered and downloaded Veusz today, and started to use it with several tutorials. After importing my data from a .csv file (that I correctly preview in the 'Import window'), I try to select the data I want to appear along the x and y axis; when I click on the arrow near 'X data' and 'Y data', nothing appears and I cannot choose anything to appear on my xy graph.
I tried several times to close and open the software, nothing changes. Here is a picture of my window: 
I got the answer - which is in fact really simple. I just had to select the English style for the numerics (I'm actually on a French computer). It went well after that.