Strange Sorting results on a Text Field

[Tom Weber]

Hello,

  have a strange response in a query with sorting.
  I sort on a field which is :

  <field name="testfield" type="text" indexed="true" stored="true"  
multiValued="true"/>

  in this field mostly 32 byte md5's are saved, mostly only a single  
entry but also up to 5.

  when I do a search like this : "+testfield: 
(fde34c51739462d9486140601dcfb7bf 63af20144c2cbae1ec4dc0bc2e9d2c2f  
3cf8e32bf2b9384447d52318a72fd4b1) ;testfield asc"

  I get the following results:
        <arr name="testfield"><str>c10c9bf4ef3f1bc30aedf83b96a9ce16</str></arr>
        <arr name="testfield"><str>c10c9bf4ef3f1bc30aedf83b96a9ce16</str></arr>
        <arr name="testfield"><str>c10c9bf4ef3f1bc30aedf83b96a9ce16</str></arr>
        <arr name="testfield"><str>c10c9bf4ef3f1bc30aedf83b96a9ce16</str></arr>
        <arr name="testfield"><str>c10c9bf4ef3f1bc30aedf83b96a9ce16</str></arr>
        <arr name="testfield"><str>4302516b91b743a8972120f52d309a72</str></arr>
        <arr name="testfield"><str>c10c9bf4ef3f1bc30aedf83b96a9ce16</str></arr>
        <arr name="testfield"><str>c10c9bf4ef3f1bc30aedf83b96a9ce16</str></arr>
        <arr name="testfield"><str>c10c9bf4ef3f1bc30aedf83b96a9ce16</str></arr>
        <arr name="testfield"><str>c10c9bf4ef3f1bc30aedf83b96a9ce16</str></arr>

  I have no idea why position 6 is in this search, because the XML  
entries are correct too.

  Any Idea where I may search for the error ?

  Also, does somebody has a link where the benefits of "multiValued"  
are explained ?

  Thanks,

  Tom