Ok I will try to give you all details you need:
Plugins : N/A.
I am referring to an auto-complete list that popups while writing a piece of code without hitting CTRL+Space.
But after checking: that 's the same list, but I'm sure I never hit CTRL+Space.
I upgraded the dev version of Sublime Text, and it seems OK so far.
Current Version : 2144.
but if it happens again I'll try to take a screenshot.
Thanks again for your support.