suggestion is: be smart and boo when there is something to boo. Booing their first appearance on the field, after you never booed them in pregame and then you played their fight song for them, at the same time that *your* own team is still coming onto the field and your marching band is still playing your fight song makes it look like they're in your head. I think it's more disrespectful to ignore them and keep cheering for your team at that moment, then boo them when they do something boo-worthy.
Tough crowd today.