Ubuntu – Computer crashes (segfaults?) after upgrading from 1GB RAM to 2GB

I have a HP Compaq Presario F500 (an F579WM). I replaced the 1GB(2x512MB) of RAM in it with 2GB(2x1GB). Since this upgrade the computer will switch to a text screen, with what looks like a backtrace or something. It often says something about a double fault or null pointer dereference. It does this rather unpredictably, though it tends to happen when you are trying to do something (but will still happen if you leave it long enough). It often happens with Firefox/Chromium (it could be me, but sometimes it seems like scrolling tends to cause it). It looks like it lists different programs (compiz, chromium-browser, etc).

I have run memtest for 10+ hr and got no errors. If if try each stick of RAM individually, it works fine. I have tried using the Nvidia driver. I've tried using the Nouveau driver. I've tried using no 3d at all. Still happens. If I run Windows, I don't experience any crashes in Windows. (So it must be some bug/setting problem with Ubuntu).

So, how do I fix this(preferable) or get the information to report a bug?

More Details:
The 2GB of memory is matching; they are the same exact item. This model of laptop has two slots and (supposedly) support 2GB of RAM. Before I upgraded the RAM, I had two sticks at 512MB each in it. I replaced those with two sticks of 1GB each (which are the same product as each other). The odd thing is that the computer works fine in Linux if I use one stick of 512MB and one of 1GB. (Windows works fine with two sticks of 1GB)

Dmidecode says the maximum RAM is 2GB, so I shouldn't be over the limit.
[Output of sudo dmidecode]

After googling, I found this: https://lkml.org/lkml/2011/3/27/17 If this is the same problem, how long will it take for the fix to be included in Ubuntu?

[Example error screen (reptyped)]
[2nd example of error] [A third and fourth example] – Retrieved by SSH and tail -f /var/log/syslog