Then the solution is as suggested below:
In the OnLoad handle hiding the ISV buttons in a separate funtion and attach the onresize to the form.
attachEvent(“onresize”,HandleButtons);
function HandleButtons() {
// HandleButtons
switch (parseInt(crmForm.all.statuscode.DataValue)) {
case 3: // Received
HideIsvButton(new Array(“Assign to Investigator”, “Assign to Coordinator”, “Approve Complaint”, “Close Complaint”));
break;
case 6: // Register
…
}