This happens to me daily freezeing, BSOD, and sometimes it will half freeze, where the screen turns on and off, and I can only move the mouse very slow and then it stops again.
I've found this laptop (same one 1558, i7) to be the most unstable machine I've ever owned! It's frozen again as I type on my Mac (Which I never have to reboot), but I was googling what the issue is and I came on this thread.
I called Dell support about my laptop, they have no clue and just ask me to re-load everything again... since this happens to a lot of people, I assume it's a problem with the laptop, and not just _MY_ laptop.
If you hear any fixes, please let me know in this thread!