OK, I have been at this for about 6 hours now. I am running Ubuntu Dapper Drake 6.06 LTS.

I have an AMD X2 4400+ dual core processor. I have been trying to use the k7-smp kernel so that I can actually use both of my cores. I went into synaptic package manager, and of course it automatically chooses all of the latest pieces needed, including the appropriate restricted modules (I have 2 7800GTX's in SLI mode, so I need the Nvidia drivers).

It all downloads and installs fine (the kernel that it defaults to download is 2.6.15.25-k7). But after about 2-5 minutes of use after I boot into this kernel and log in, my entire computer locks up. Mouse doesn't move, keyboard shortcuts don't respond. I have to manually reboot with the power button. Reminds me of the days of Windows 3.1.

So I thought that I would step it back and get the previous kernel (2.6.15-23-k7). But when I try to download it, synaptic wants to automatically put all of the latest software with it that depend on the newer kernel. I couldn't get it to cooperate, so I figured, what the hell, I'll try it.

I reboot, choose the older kernel, and after the Ubuntu loading screen, I get the X failure screen telling me that it couldn't start X. I figured that this was because the restricted modules wanted to work with the newer kernel and not this one.

So I reboot again, this time to the newer k7 kernel (2.6.15-25-k7) only to find that after the Ubuntu loading screen, nothing gets sent to my monitor. My LCD power light goes orange dictating that it is no longer recieving a signal from my video cards.

The only way I can work in Ubuntu is to use the latest 386 kernel, and that sucks because I'm running on only half of my physical cpu hardware.

Is there a better way to do this? I've tried the sudo apt-get, but it does the same exact thing as synaptic, getting all of the latest stuff, not letting me have anything older.

Suggestions?

First, do a clean system reinstall. Then, you want to get the "smart" package manager at http://labix.org/smart After you have that installed, then you can choose what packages that you want to install by manually downloading them and looking them over before you install them.

This is the exact problem I have been experiencing. I have very similar hardware ( Athlon X2 4200, 2 x NVidia GeForce 6800XT, running 32-bit Ubuntu). It turned out in my case that the combination of the smp kernel 2.6.15-26-k7 and the nvidia driver (nvidia-glx-1.0.8762+2.6.15.11-3_i386.deb) caused the system to lock up completely after 3-5 minutes of use. I have had to revert to the nv driver to solve the issue, but it isn't a real fix as I am out 3-D support. I have been searching for info on this but have only come up with old info on bad nvidia drivers causing this back in 2005. Does anyone have an Athlon X2 and Nvidia SLI setup that works with an smp kernel?

Well I have come across a fix for the random lock-ups when using SMP kernels and Nvidia drivers in Ubuntu. I added the following kernel parameters to grub on the SMP kernel line

pci=nommconf
idle=poll

It fixed my system. Uptime now 6 days with no crashes or hangs. I hope this helps someone.