but in my personal opinion it is always nice to inform the user if the code does not work in any specific release (worth noting). So if it fails in IE6, who cares... if it does not work in safari or IE7... well I wouldn't go so far as to provide them with those solutions, rather mention "Hey, this fails in IE7. If IE7 is a concern then you will have to do a little research into how to make it work there as well.".
I think this is completely fair, the OP has his answer, and also has a good starting point on what to search for compatibility concerns.