Why do some teleports have a Cancel button, and others do not?

Why do some teleports have a Cancel button, and others do not?

Rock

The viewer seems to hide the Cancel button as soon as it receives any message from the destination sim. It looks like there are 5 stages:

* start: "Viewer has sent some kind of TeleportRequest to the source simulator"
* requested: "Waiting for source simulator to respond"
* moving: "Viewer has received destination location from source simulator"
* start arrival: "Transition to ARRIVING. Viewer has received avatar update, etc., from destination simulator"
* arriving: "Make the user wait while content 'pre-caches'"

The "start arrival" state is the one that hides the cancel button.

<random guess>
It could be because at that point your data is transitioning from one sim to another and backing out of that would make no sense because the "source" sim probably already handed you off and you have nowhere to go back to.
</random guess>

If I guessed wrong, at least the thread got a bump .

That cancel button has translated to "do you want to log off?" for me, because lately, whenever I cancel, I get disconnected from the region and am forced to log off.

A cancel button only seems to be provided if the teleport is going to be successful. The teleports where the progress bar never moves and it just hangs there never have a cancel button, unless you count the "X" at the upper right corner of your screen.