Our computers were not at the same level of windows update when I encountered the problem.
The first time I had the issue, I had just finished the installation of a one windows update on my computer. So I tought that could be the cause of the problem and tried on my gf's computer. And I'm abolutely sure this one windows update wasn't installed on it. So I guess it rules that out.
I'm on a 32-bits Windows 7 Ultimate, she's on a 64-bits Windows 7 Home. We both use BitDefender Internet Security 2012 and "usual" software like LibreOffice (3. 4 for her, 3. 5. 7. 2 for me), Firefox (last version 20. 0. 1), Satsuki Decoder Pack (I could surely be wrong but I can't even begin to think of a way a Decoder Pack could interfere with Aurora. Or an office suite for that matter
), CCleaner,. . . I can't make a complete list of our common software right now, but can give it a thought later if it seems useful.
And I was _that_ close of fighting my first space battle ! This is so frustrating !