Hi Peter,
I cannot reproduce that behavior. Did you try a different browser/workstation?
Links only open in new tabs/window if they have a "target" attribute set and
if that target attribute is differs from the name of the current window.
Could you verify the link behind the icon does not have a target attribute set?
I use this action_url:
action_url /pnp4nagios/index.php/graph?host=$HOSTNAME$&srv=$SERVICEDESC$' class='tips' rel='/pnp4nagios/index.php/popup?host=$HOSTNAME$&srv=$SERVICEDESC$
But this seem to make no difference, i tried yours too.
Do you use the standard status-header.ssi?
-> https://github.com/sni/Thruk/blob/master/ssi/status-header.ssi-pnp
Bye,
Sven