Re Show Box. Did you get a notification about a new version being available when you started this application? If so, did you click Remind Me Later or the other "yes, update please" type button?
I've not upgraded yet (I tend to wait until a new version of something has a killer feature I can't "live" without, or an older version no longer functions correctly), but with my installation of Show Time, I see a small advert at the bottom centre of the screen, and when I click on a film, I get the next screen where it asks if I want Low/Medium/High quality, to download or watch it now, and whether to use the app's internal player. Is it at this point you're presented with a full screen advert, or not until you've actually clicked the Watch Now button?
I think I know the problem. I didn't see the full screen advert until after the film had comeplted. This makes me think Show Box believes you've watched the movie (because a video playing app isn't working) and shows the advert instantly.
1) If you've currently got Use Internal Player ticked, untick it. When you click Watch Now, select MX Player and Always.
2) More likely, I think you've not got that option ticked, and you've accidentally clicked on the wrong video player app in the past, then clicked on ALWAYS, instead of JUST ONCE.
To fix this, install Default App Manager Lite -
https://play.google.com/store/apps/details?id=com.appiator.defaultappmanager&hl=en
You could just go directly to the mis-behaving Video Player's entry in the Apps entry of Androids settings, but I'm assuming you don't know which one has been selected.
Anyway, open the Default App Manager Lite program, scroll down to Video, click on it, then select the Clear Default option. This will then take you directly to the app that was accidentally set as a default. Scroll down, click the Clear Defaults button.
Reboot for good measure (probably not needed, but never does any harm).
Restart Show Box, and this time when you click watch now, I would select MX Player. For now, select Just Once. When you know Show Box is working happily, unless you intend to use other video playing apps, select Always the next time.
3) Small possibility that your internet isn't working (on the DroidBOX device). This may cause the video player to quit as it can't find the film, then the advert is shown. If steps 1) and 2) didn't help, make sure you can visit a website in the Android browser.
Re telling an XBMC add-on to download films to the external SD card, before you click on the add-on's name, highlight it and press the MENU or C (if you have a QWERTY keyboard on your remote control) button. This will bring up a window, select the last option (add-on settings??). If you can download films, instead of streaming them, there should be an option on of the tabs where you can select where to save files to.
I've had a look through Show Time, and there doesn't seem to be an option area within the GUI. It looks as though you need to wait for a download to complete, then move the file by hand. It stores Films/TV Series in the /sdcard/show_box folder.
So navigate there (ES File Explorer is my preferred app for this sort of thing), click on the sdcard link on the left (if you can't see a sdcard link on the left, either update ES File Explorer ( see
Google's Play Store - Signing In And Auto-Updates ) , or go to the root ( / ) and then mnt/sdcard)
Once there, long click on the downloaded movie/TV episode, and select Cut. Now click on the external_sd link on the left hand side (or navigate to /mnt/external_sd or your preferred location), and once in the directory you want to store videos in, click the paste button at the bottom.