Timeline problem with spells

Dear all,

I am using the statistical package R to create GEXF Files. The data I analyze consists of forum users who do no participate all the time in the forum. So I used spells in the GEFX file.
The problem that occurs is the following: when I move the green slider in the time line window, the dates displayed in the silederbar itself change when I move the slider to the extreme right. Then only a part of the entire time is being displayed and I cannot display all my data anymore.

I'd appreciate any help!

This is a minimal XML GEXF File that produces the error:

<?xml version="1.0" encoding="UTF-8"?>
<gexf xmlns="http://www.gexf.net/1.2draft" version="1.2" xmlns:viz="http://www.gexf.net/1.2draft/viz" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.gexf.net/1.2draft http://www.gexf.net/1.2draft/gexf.xsd">
  <meta lastmodifieddate="2012-02-16">
    <creator>Gephi 0.8</creator>
    <description></description>
  </meta>
  <graph defaultedgetype="directed" timeformat="date" mode="dynamic">
    <nodes>

   <node id="29323" label="boingboing" start="2007-09-20" end="2007-10-01" >
      </node>

   <node id="29320" label="estepitino" start="2007-04-17" end="2007-04-18" >
      </node>

      <node id="29321" label="sirpi" start="2007-02-27" end="2007-04-22" >
         <spells>
            <spell start="2007-02-27" end="2007-03-03" ></spell>
            <spell start="2007-03-05" end="2007-03-07" ></spell>
            <spell start="2007-03-09" end="2007-03-10" ></spell>
            <spell start="2007-04-22" end="2007-04-23" ></spell>
          </spells>
      </node>

      <node id="29322" label="kafficho" start="2007-02-23" end="2007-02-27" >
         <spells>
            <spell start="2007-02-23" end="2007-02-24" ></spell>
            <spell start="2007-02-27" end="2007-02-28" ></spell>
          </spells>
      </node>
     </nodes>
  </graph>
</gexf>