Call to undefined function Insert()

Hi, I can't figure out this error:

Fatal error: Uncaught Error: Call to undefined function Insert() in D:\xampp\htdocs\dashing\test.php:10 Stack trace: #0 {main} thrown in D:\xampp\htdocs\dashing\test.php on line 10

I'm using DB::Insert multiple times prior to this, but this one fails.

		
$notedata = array();

$notedata["leadid"] = 11;
$notedata["note"] = "test";
DB:Insert("note", $notedata);

However the following works:

CustomQuery("insert into note (leadid,note) values (11, 'test')");

This also works:

$contactdata = array();
$contactdata['leadid'] = 11;
DB::Insert("contact", $contactdata);

Here's another example:

$contactdata = array();          // works
$contactdata['leadid'] = 11;        // works
$contactdata['firstname'] = "test";   // works
DB::Insert("contact", $contactdata);  // works

$notedata = array();                 // works
$notedata['leadid'] = 11;           // works
$notedata['note'] = "test";         // works 
DB:Insert("note", $notedata);       // dies!!!