You could try this for debugging:
echo $pts_groupa."<br>";
echo $pts_groupb."<br>";
$query=sprintf("UPDATE table1 SET current_score = %d",$pts_groupa+$pts_groupb);
echo $query;
mysql_query($query);
It might also be useful to see your script, just remember to do this when you post (remove the *):
[php]
your script here
[/php]