Code outputting odd XML

So here is the code: About 99% of the time it returns the XML listed under "Good Return" but almost randomly it is returning the code under "Bad Return". I echoed out all of the $ToID's and there is no weirdness (Only long integers)

 

foreach ($xml->result->Accounts->row as $a) {

 

$ToID = (String) $a->FL[0];

$FromData = (String) $a->FL[1];

$ToXML .= '<row no="' . $UpdateCount . '">';

$ToXML .= '<FL val="Id">' . $ToID . '</FL>';

$ToXML .= '<FL val="' . $ToField . '">' . $this->FixID($FromData) . '</FL>';

$ToXML .= "</row>";

echo "$ToID <br>"; //For debugging

 

---- Bad Return (Its missing a < after ID)

 

<row no="162">

<FL val="Id">1058030000000072643/FL><FL val="MemberCode">Firms.338</FL>

</row>

---- End bad return

 

---- Good Return

<row no="163">

<FL val="Id">1058030000000072642</FL>

<FL val="MemberCode">Firms.337</FL>

</row>

---- End good return