$ perl -lwe'$x[2]="x";print @x'
Use of uninitialized value at -e line 1.
Use of uninitialized value at -e line 1.
x
$
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Like kwoff and mortis said, one of your patterns isn't matching before /$ID/, so there's a hole in your data.  Notice, that if one message matched it's value would remain for all those after.  You should probably put the    @data = ('','','','','');   inside the loop.

  p