Hum maybe it is something to do with the cards Havoc seems to be the root of your problem.
Have you tried reseating the cards RAM sticks or anything that can be unplugged and then plugged in again?
Maybe it might be worth running a memtest too if you haven't already because it seems to be revolving around something not hanging on to a boot very well?
All you need to do is burn a bootable disk for memtest set the machine to boot from optical - it will boot into the test the OS is not involved and let it run. Now this can take some time and you need at least 7 passes it could be something simple like a bad stick or chip on a stick. Any errors will show up as reported errors.
Memtest download - http://www.memtest.org/ *
Before you do that why not take all the sticks out then try a boot with each one individually 1, 2 and 3 if one does the problem then ok you have found the problem most likely if they are all good boot with two sticks in and then three and in different slots. I know this is tedious but quick. It just might be that the sticks are not matched together too well. Personally I like to buy them as sets of one two three or four.