Well, it turned into a critical issue for me. FSO tonight had a new version of the Germany terrain. The terrain would get just about done and then loose connection with the host. When re-entering, the pop-up window that asks if you want to cancel or resume the download does not appear and you are forced to hit the upper-right X to exit, Alt-F4, or disconnect from the internet so the game thinks it has lost connection with the host. Since FSO is all I do, that is like $5 down the drain.
I am going to try and download the game from the web site and see if they updated it there. Did not think to try it until typing this.
Edit:
I forgot to mention that deleting the temp files in the Aces High/temp folder allows you to attempt another new terrain download. After 4 attempts on dial-up, it was not possible to make the start of the frame in FSO before they closed the fields.
And yes, the terrain on the web site is an older version and downloading from there did not help. And just to reiterate what B4Buster said in case you missed it, after clicking the cancel button during the download, the "Are You Sure" window does not pop-up either and the application just sits there waiting for a response from the user.