workaround until api problem is sorted out...
PHP Code: 
//To get the link
echo uploadfsc(getcwd()."/x.txt",'manohar_pandey@yahoo.co.in','Random');

//function code
function uploadfsc($x,$email,$pass){
    
$var curl('http://api.filesonic.com/upload?method=getUploadUrl&u='.$email.'&p='.$pass,'');
    
preg_match('/"http:(.*?)"/',$var,$match);
    
$url trim(stripslashes($match[0]),'"');
    
$post = array('files[]' => "@$x");
    
$ch curl_init();
    
curl_setopt($chCURLOPT_URLtrim($url));
    
curl_setopt($chCURLOPT_POST1);
    
curl_setopt($chCURLOPT_FOLLOWLOCATION1);
    
curl_setopt($chCURLOPT_POSTFIELDS$post);
    
curl_setopt($chCURLOPT_RETURNTRANSFER1);
    
$result curl_exec($ch);
    
$result curl("http://www.filesonic.com/user/login",array('email'=>$email,'password'=>$pass,'redirect'=>'/','rememberMe'=>'1','controls[submit]'=>'submit'), ""true);
    
preg_match_all("/Set-Cookie: (.*?) /",$result,$matches);
    
$cookie="";
    for(
$i=count($matches[1])-1;$i>=0;$i--)
    {
        
$match $matches[1][$i];
        
$cookie_var str_ireplace(strrchr($match,'='),"",$match);
        if (
stripos($cookie,$cookie_var)===false)
            
$cookie.=$match;
    }
    
$result curl("http://www.filesonic.com/filesystem/browse/D0/1",array('queryString'=>basename($x)),$cookie.'fs_orderFoldersBy=date;fs_orderFoldersDirection=desc;');
    
preg_match('/<input type="checkbox" (.*?) rel="(.*?)"(.*?)\s*(.*?)"'.basename($x).'">/i',$result,$match);
    if(
$match[2]!="")
        return 
"http://www.filesonic.com/file/".$match[2];
    else
        return 
"";
}
function 
curl($url$postdata$cookie ""$header false)
{
    
$ch curl_init();
    
curl_setopt($chCURLOPT_URL$url);
    if(
$header == true)
        
curl_setopt($chCURLOPT_HEADER1); 
    if(
$cookie != "")
    {
    
curl_setopt($chCURLOPT_COOKIESESSION1);
    
curl_setopt($chCURLOPT_COOKIE$cookie); 
    }
    if(
$postdata != "")
    {
        
curl_setopt($chCURLOPT_POST1); 
        
curl_setopt($chCURLOPT_POSTFIELDS$postdata); 
    }
    
curl_setopt($chCURLOPT_RETURNTRANSFER1);
    
curl_setopt($chCURLOPT_CONNECTTIMEOUT60);
    
curl_setopt($chCURLOPT_TIMEOUT1200);
    
$source_code curl_exec($ch);
    
curl_close($ch);
    return 
$source_code;