mssql_fetch_assoc没有输出（但是vardump显示数据）

I have a very odd situation where my while loop 'sometimes' works and 'sometimes' not, but I can't find a common denominator. I am basically pulling an array from a stored procedure in PHP, something I have done numerous times before.

First off, I have this:

$rowpayments = mssql_fetch_assoc($rspayreview);
 echo '<!-- DEBUG '; var_dump($rowpayments); echo ' -->';

This particular code DOES output the array in EVERY instance.

But when I attempt to while through the results and output them, sometimes the loop doesn't get to the debug code.

while($payinfo = mssql_fetch_assoc($rspayreview)) {
    echo '<!-- DEBUG CHECK 2 !-->';
    //echo $payinfo['CardholderName'];
    // other examples
}

There are time the debug check 2 doesnt even fire, but yet, sometimes it does and it shows me everything in the array.

For your reference, here is a var_dump example that outputs, but yet, doesn't show up in the while loop.

<!-- DEBUG array(7) {
  ["ResIDLink"]=>
  int(165476)
  ["PayDate"]=>
  string(26) "Mar 16 2015"
  ["CardholderName"]=>
  string(13) "xxxx"
  ["Right4CCNum"]=>
  string(4) "4984"
  ["ChargeAmount"]=>
  float(300)
  ["Paid"]=>
  int(1)
  ["CCType"]=>
  string(4) "VISA"
}

Does anybody have any thoughts on this? It would be GREATLY appreciated.

EDIT, as an FYI, i HAVE attempted using a foreach, however, it winds up giving me Illegal string offset errors instead.

foreach( $rowpayments as $payinfo ) {