[Problem]
After a fresh installation on a 100% checked brand-new SSD, every other time the OS boots up, it throws you to a irresponsive black screen with a blinky cursor and thats it. Pushing reset a few times leads to the system booting normally (it appears to die before really initializing anything, thus the resets did not trigger any fsck check of teh HDD). Awkward - Disk is 100% ok, actually tested with 2 SSDs, all drivers are updated, and the friggin' Logs are EMPTY, as in no errors and not even warnings, all looks smooth.
[Solution]
After some reserach i actually found a solution in a Kernel Bug ticket: Some SSDs are too fast which leads to the above symptom every other boot (worse if the SSD got everything for the boot cached - cold start helps here) due to a racing condition. Someone also posted the solution there, it was a single line to put into some boot-up script, but in my neverending wisdom i've deployed the fix, had it tested a few days (so far the problem is showing up again at all), and forgot about it.
So i'll got and look for it to post it here because that one was a brainfuck. The good news is, that bug was accepted as bug and announced to be fixed soon, as apparently a lot of users running high-end boxes with very fast SSDs suffer from this issue!
Edit:
Found it. Many sites are already covering the problem as its a pain for MANY people out there (theres a lot of SSD users by now!), so here some links with the possible fixes:
http://www.adminreseau.fr/ubuntu-lightd ... orkaround/
http://www.webupd8.org/2013/01/ubuntu-l ... using.html
Looks like they require to install a different window manager.. i'll post the solution i used earlier as it did not require to get rid of lightDM as soon as iam at that box again and can check the file for changes.