[Orgmode] Plotting date on xaxis

[Johan Ekh]

Hi all,
I try to plot a table looking like this

     |       Date    |   Kg |
     |-----------------+--------|
     | 2010-02-21 | 95.0 |
     | 2010-02-22 | 93.0 |
     | 2010-02-23 | 92.0 |
     | 2010-02-24 | 91.5 |
     | 2010-02-25 | 91.0 |
     | 2010-02-29 | 92.0 |
     |                  |        |

with the dates on the xaxis using 

#+PLOT: title:"Weight" ind:1 deps:(2) type:2d with:linespo set:"xdata time" timefmt:%Y-%m-%d set:"yrange [90:]" 

but no plot is generated. If I remove <set:"xdata time">, the plot is generated but without interpreting the dates as dates.

Can anyone see what I do wrong?

Thanks in advance,

Johan