it way not be passing a value because there is no value attribute for the weight text box.
change:
<input name="Weight_<?php echo $RepeatSelectionCounter_1; ?>" type="text" size="10" maxlength="3" />
to:
<input name="Weight_<?php echo $RepeatSelectionCounter_1; ?>" type="text" size="10" maxlength="3" value="" />