"Problems with the linear Regression"

Hello,

this post refers to the Bug 497  I've send Friday. There I wrote that there ist a problem with the X- and split validation. Now a little upgrate: The validation operators are not the wrongdoer. The error occurs as well when I only use the linear regression operator and choose less than two attributes with the select attribute operator. When I generate two regular attributes with the generate data operator everything works fine?

<process version="5.1.002">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="5.1.002" expanded="true" name="Process">
    <process expanded="true" height="538" width="614">
      <operator activated="true" class="generate_data" compatibility="5.1.002" expanded="true" height="60" name="Generate Data" width="90" x="45" y="210"/>
      <operator activated="true" class="select_attributes" compatibility="5.1.002" expanded="true" height="76" name="Select Attributes (2)" width="90" x="179" y="300">
        <parameter key="attribute_filter_type" value="subset"/>
        <parameter key="attributes" value="att1|att2"/>
      </operator>
      <operator activated="true" class="linear_regression" compatibility="5.1.002" expanded="true" height="94" name="Linear Regression (2)" width="90" x="313" y="255"/>
      <connect from_op="Generate Data" from_port="output" to_op="Select Attributes (2)" to_port="example set input"/>
      <connect from_op="Select Attributes (2)" from_port="example set output" to_op="Linear Regression (2)" to_port="training set"/>
      <connect from_op="Linear Regression (2)" from_port="model" to_port="result 1"/>
      <connect from_op="Linear Regression (2)" from_port="exampleSet" to_port="result 2"/>
      <connect from_op="Linear Regression (2)" from_port="weights" to_port="result 3"/>
      <portSpacing port="source_input 1" spacing="0"/>
      <portSpacing port="sink_result 1" spacing="0"/>
      <portSpacing port="sink_result 2" spacing="0"/>
      <portSpacing port="sink_result 3" spacing="0"/>
      <portSpacing port="sink_result 4" spacing="0"/>
    </process>
  </operator>
</process>

Because of this problem I can't use the forward selection operator too.

Best wishes

Matthias