Hmm, by default that little downward pointing triangle is at the right end of the tab bar. Could you go back into Customize mode and try dragging anything that appears to the right of it back around to the left of it?

You only see the window controls if you are in full screen mode (press F11 to toggle) and this item is always at the far right and isn't customizable AFAIK.

id="window-controls"
pack="end"
skipintoolbarset="true"
ordinal="1000"

@jscher2000 - good to know.. then maybe it's one of my add-ons causing havoc or something to that effect. Didn't find anything to drag in customise mode.. any other suggestions? Thanks

@cor-el - Thanks but I think you've misunderstood my question (or I've misunderstood your answer).. I don't need to move the window controls, just the list all tabs arrow.

Ok... I clicked 'restore defaults' in the customise menu and that seems to have sorted it at least for now. Will keep an eye on it in case it's due to some add-on. Thanks jscher2000 - wouldn't have tried that if you hadn't mentioned that it should be on the right by default.

Hmm, all I meant was that the tiny triangle should be the last thing on the bar. Does yours look like this in Customize but then when you exit Customize something else appears to the right?

Edit: Our posts crossed, so never mind.