Vista - Vista Home Premium x64 BSOD caused by netio.sys

I could use some help resolving a BSOD I keep getting, caused by netio.sys.
It started quite a while ago after I installed some software (sorry, can't
even remember what the software was now) and I have tried everything I know
of to fix it. It happens about 50% of the time and is always at exactly the
same place while booting the system up, at the Vista loading screen. The
system does not usually do a memory dump, it says 'initialising' and then
just stops. I have to manually reset, and then it will work fine until next
time I boot up.

Steps I have taken so far:

Unistalled the software
Tried system restore
Ran chkdsk (this finds errors with the file system and repairs them, but
does not seem to make any difference)
I was going to reinstall Windows but I noticed on some forums people had
tried this and it did not fix it. Also, my disc sometimes doesn't work, and
wasn't when I wanted to try it (DVD drive related problem I think).
I also found a hotfix but did not install it as it does not seem related to
my problem, please let me know if I should install this.

I also have a seperate issue regarding networking. If at any time I use the
sleep/hibernate functions of Vista, when I wake the system I have no network
connectivity at all. For this reason I have to fully shut down my PC once
I've finished with it, which negates quickness of Vista when booting. I have
two onboard adapters (gigabit) and it happens on both. Again I have tried
everything to get it to work:

Restart
Shutdown and boot up again
Reinstalled drivers
Used different drivers
Used newer drivers from nVidia website instead of Windows Update
Setting static IP address, gateway, etc

The only thing that will make it work is shutting down and actually turning
off mains power for a time, before booting back up. then it will work. If I
don't shut off mains power it will not work. My motherboard is a Asus
P5N32-E SLI PLUS which has 2 nVidia nForce network controllers, and I think
it has an nForce 680i chipset.

Please let me know if you have any suggestions for either problem.

Thanks.