I was not able to make your answer work, jasotastic, but there's a lot about scripting I don't understand. However, this has worked for me (checking "Specify Item Values" on the Binding tab, where the list choice 'Other' has a value of 4):
var othercut = Cut.rawValue
if(xfa.event.newText == "Other"){
Other.presence = "visible";
}
else{
if (othercut == 4){
Other.presence = "visible";
}
else{
Other.presence = "hidden";
}
}
This would be for the "Tool" dropdown; corresponding changes are made in the "Cut" dropdown.
I had tried going with logic operators before and got nowhere. I really do like the formula that works in the both cases, though.