mysql> select 'David!' LIKE '%bob%'; appears to be case sensitive but should not be?

I have a Select querie thats driving me mad...

<?

$query = "SELECT * FROM news WHERE article
LIKE'%".mysql_real_escape_string($_GET["abc"])."%' OR heading
LIKE'%".mysql_real_escape_string($_GET["abc"])."%' ORDER BY issue
DESC";
$result = mysql_query($query)
or die ("no can do.");
while($row = mysql_fetch_array($result))
{
?>

It is case sensitive and I don't want it to be - when searching for
'bob' and Bob is typed in it failes to return any rowes. I have done a
long search on this group and others and all seem to have a problem
because they WANT it case sensitive - from the mysql page "By default,
MySQL searches are not case sensitive" ...
so then why is mine? The database is set up as a longtext and the
Collation is armscii8_bin?

If anyone can help me with this I would be very happy.

Thanks