After some investigation I can tell that aforementioned bahaviour is most probably caused by opening the INDD file by using AIR API (file.openWithDefaultApplication()). When file is opened by user this behaviour is not observed, but when INDD is opened from AIR application, it results with disabling spacebar shortcut. What is even more strange, the shortcut is disabled not only in InDesign, but also in Illustrator. Photoshop works fine...
Geez, Adobe, you're giving me so much headache...
Corrected typos Message was edited by: Maciej Przepióra
This just happened to me and I found tons of posts saying it was related to this application or that application...for me it was Firefox. A quick quit/relaunch of Firefox and everything is back to normal. Why? I have no idea. Try quitting your other apps one at a time. Maybe you'll find your own culprit.
In my case it was also connected with Firefox, so we switched to Safari (on MacOSX). Apparently, this fixed our problem.