Problems with the mailindex

With the following template:

<Sort>
<Reverse>

<DayBegin>
<li><strong>$DDMMYYYY$</strong>
<ul>
</DayBegin>

<DayEnd>
</li></ul>
</DayEnd>

<LITemplate>
<li>$SUBJECT$, $FROMNAME$</li>
</LITemplate>

I get the following result on my mailindex:

[SNIP]

    16/07/1999 
          Re: Sv: [TLUG_BESTYRELSE] Generalforsamling, ihs
          Sv: [TLUG_BESTYRELSE] Generalforsamling, Martin List-Petersen
          SV: [TLUG_BESTYRELSE] Generalforsamling, Martin Andersen
     16/07/1999 
          Sv: [TLUG_BESTYRELSE] reviderede rules, Martin List-Petersen
          Re: [TLUG_BESTYRELSE] reviderede rules, ihs
          Re: [TLUG_BESTYRELSE] reviderede rules, Hans-Henrik Andresen
          [TLUG_BESTYRELSE] reviderede rules, ihs
          [TLUG_BESTYRELSE] Generalforsamling, ihs
     14/07/1999 
          Sv: Sv: [TLUG_BESTYRELSE] TLUG rules, Martin List-Petersen
          Re: Sv: [TLUG_BESTYRELSE] TLUG rules, ihs
          Sv: [TLUG_BESTYRELSE] TLUG rules, Martin List-Petersen
          [TLUG_BESTYRELSE] TLUG rules, ihs
     13/07/1999 
          Sv: SV: [TLUG_BESTYRELSE] Moede for udarbejdelse af vedtaegter, 
Martin List-Petersen
          Sv: SV: [TLUG_BESTYRELSE] Moede for udarbejdelse af vedtaegter, 
Martin Andersen

[SNIP]

Why doesn't it put the two days of july 16yh 1999 toghether in one list ?????
It does this several times on several dates !!

Regards,

Martin List-Petersen
TLUG Hostmaster