Remembering my previous DO tabs: Dropbox Vs Task Bar

Hi,

This is a trivial question, but I could not see the answer in the FAQ/manual. Sorry if it's obvious. I have Windows 8.1 DO 11.5 (I watch the beta's but install the full releases).
I love the feature in DO that remembers all my tabs (which I have displayed at the top) showing all the directories I currently have open to work in. It is my "working set".
I close DO when I shutdown the laptop, then come the next session open DO from the Taskbar (the PC opens DO at startup, but does not display a lister), and bang. I am back were I was when I shutdown. All the tabs (my working set) re-appear just as they were.
Recently I have been using Dropbox and when I boot the PC it sometimes says, "X files updated in Dropbox, click here to view", so I do.
It opens DO (as the replacement for Explorer), but shows just the one Dropbox folder. Hmmm. Where have my previous folders (tabs) gone?
Now I can't remember what I was working on, and Dropbox has wiped them away. I close DO in anger, but when I reopen it, it now displays the last tab set which is just the Dropbox folder..... Grrrrrrr.
It's the same when I download a file in Chrome, if I select to open the folder, it just displays that one folder and wipes my previous DO tab memory.
This is really getting to me. I cannot find how to save the current set of tabs and configure DO so that these 3rd party programmes do not wipe them and display their single directory.
I would like them to add their directory as an additional tab to my previous "working set".

I do not want to save the current set of tabs as a permanent set, as they change all the time (unless this can be done transparently). But I do want to save "the current" (working) set of tabs, and always have these available in DO however it is started.

Please could you point me in the right direction to do this?

Cheers,
Peter.

Turn on both highlighted options:

download/file.php?id=9026

YES! That's exactly it. Thank you Leo.
I did look in the Explorer Replacement options, but did not spot, or take note of, those options down there.
It's funny how these small options/changes make such a difference to the daily work process.