Description:
------------
I am inserting into 2 tables, and each time in addition to inserting a row with the correct data, a phantom, blank row is inserted. This seems similar to bug #10599 "background attribute in the body tag causes a double insert", but I am not using the "background" tag, and I can't find my error. I am using "background-color" in CSS but I don't see how this could be a problem. What is also weird is that for the "sur_subcategory" table, the data is being inserted near the top of the database table, and not at the bottom like one would expect. Another anomoly: when I use Mozilla (1.4) it double inserts into both tables, but when I use IE (6.0), it only double inserts into one table (sur_category_subcategory). 



Reproduce code:
---------------
$step1 = '';

// sur_subcat table insert
$step1 = sprintf("INSERT INTO sur_subcategory (subcat_name) VALUES ('%s')",$subname);
$result1 = mysql_query($step1);

// get subcat_id to put into sur_cat_sub table
$step2 = sprintf("SELECT subcat_id FROM sur_subcategory WHERE subcat_name = '%s'", $subname);
$result = mysql_query($step2);
$subcat_id = mysql_result($result,0); 

// insert into sur_cat_sub table
$step3 = sprintf("INSERT INTO sur_category_subcategory (category_id,subcat_id,subcat_name) 
					VALUES ('%d','%d','%s')",$category_id,$subcat_id,$subname);
$result3 = mysql_query($step3);
?>
<br>
<?
echo ("<b>Your subcategory has been submitted</b>.");
mysql_close();
?>

Expected result:
----------------
What I want is for a SINGLE row with the subcat_name to be inserted into table sur_subcategory, and a SINGLE row with the category_id, subcat_id and subcat_name to be inserted into the  sur_category_subcategory table.

Actual result:
--------------
When I insert into sur_subcategory, a row with the correct information is created. However, another row with incorrect information is created too. The same happens when I try to insert into sur_category_subcategory. Example:

when $subname = "halehtest1", and the first mysql insert is done, the sur_subcategory table looks like:

-- 
-- Table structure for table `sur_subcategory`
-- 

CREATE TABLE `sur_subcategory` (
  `subcat_id` smallint(8) unsigned NOT NULL auto_increment,
  `subcat_name` varchar(30) NOT NULL default '',
  PRIMARY KEY  (`subcat_id`)
) TYPE=MyISAM AUTO_INCREMENT=126 ;

-- 
-- Dumping data for table `sur_subcategory`
-- 

INSERT INTO `sur_subcategory` VALUES (124, 'halehtest1');
INSERT INTO `sur_subcategory` VALUES (125, '');