I run a small exchange, and we are having a problem with the DIMECOIN wallet. when sending amounts over 1 million coins. we get the following message when error reporting turned on. I can't for the life of me determine what the error is.

Fatal error: Uncaught exception 'Exception' with message 'Request error: Array' 
stack trace: #0 ../class.wallet.php(36): jsonRPCClient-     >__call('sendtoaddress', Array)
#1 ../class.wallet.php(36): jsonRPCClient->sendtoaddress('7EFMZkPb6sHhKgk...', 69986000) #2 
../withdrawalqueue.php(128): Wallet->Withdraw('7EFMZkPb6sHhKgk...', '69986000', '1', 'DIME') #3 ../index.php(334): include('..') #4 {main} thrown in ../jsonRPCClient.php on line 

Here is my code:

if ($total > 1000000) {
        return $this->Client->sendtoaddress($address, (double)round($total, 2));
}
elseif($total > 10000000) {
        $amt2s = $total * .1;
        $i = 0;
        do{
            return $this->Client->sendtoaddress($address, round($amt2s));
            $i++
        }
        while($i < 10);

}else{
        return $this->Client->sendtoaddress($address, (double)sprintf("%.8f", $total));
    }