Does anyone have a reference design 5870 (or maybe a 5970?) for sale near Detroit?

Is anyone interested in such a deal?
I've got a pair of Sapphire 5830s, low hours, sitting.  I'd like a reference design 5870 (XFX preferred).
If you're of the mining type, those 5830s are good for a combined 600 MH/s in exchange for your 400 MH/s!

I need to get my Battlefield 3 rig tuned up, so I'm looking to partner up my XFX 5870, but I'd be OK with any reference design, I suppose.
I've got a little bit of heatware and good ebay feedback.

I shouldn't jump into something like this, but I'm totally perplexed by your last post here.

I was in Utah last year.  I'm not sure if that qualifies as "recently" in your context since I don't have any idea what your context is.  Have they started paying for goods & services with gold coins there?  We used greenbacks when I was there.  Are they mining for gold?  How does Utah relate?
I'd suggest that there's universal agreement that gold has been held as an object of value fjor one reason or another for the last 6000 (or some number of) years, but I don't see how that makes it "money" today.
Finally, I have no idea of the point of your chart.  I see that it's got a rainbow of colors and is triangular, is this a gay thing?
These are all honest questions, I'm not trying to challenge anything (although I don't believe that "gold is money").

You're discounting the fact that CPUs (like GPUs) use more energy when they're working hard than when they're at idle.

It doesn't make financial sense to mine with 1 CPU because you spend more for the electricity than you'll get out of the coins, that won't change if you add a lot more CPUs.
A covert, virus-spread botnet would be effective for the creator because he's not paying for the electricity.

What do you have your AGGRESSION set to?
Tweak that up a notch or two at a time and see the tradeoff between GPU utilization and display responsiveness.

Also, check out the mining forums for the threads on how to get Cat 11.6 installed; ubuntu installs an older driver level that doesn't let you exceed those limits you posted the dump of.  It also installs the driver in a non-standard way, but there's a Cat installation wiki that tells you how to get from the ubuntu-installed driver to a generic install.  If you have a hard time finding the posts, check my "see all posts by" I posted a link to it a couple of days ago.

Have you checked the bottom of this wiki?
It's got info for how to get 11.6 to work if you have the driver ubuntu installed on its own as well as other possibilities:
http://wiki.cchtml.com/index.php/Ubuntu_Natty_Installation_Guide#Issues

Fortunately, with the Catalyst 11.6, you can overclock beyond the BIOS limits under Linux now.

I wish I could be more helpful, but had a hard time getting 11.6 installed properly after having ubuntu installed ATI drivers.
However, if you go to the AMD driver download page and look through the release notes link, it has instructions on how to uninstall the old drivers and install the new ones.  I wound up deactivating the ubuntu-installed ATI drivers under SYSTEM, HARDWARE DRIVERS and running the general 11.6 install.  It wouldn't run aticonfig because I think the ubuntu install sets unusual file structures in place that the ATI  generic install doesn't undo, somehow.  Eventually, I went back to activating the ubuntu-installed ATI drivers and got my overclocks, so I was content.
I should have tried searching more.  Here's a wiki that details how to get 11.6 on 11.04, including a section on how to remove the ubuntu-installed driver config:
http://wiki.cchtml.com/index.php/Ubuntu_Natty_Installation_Guide

Yet it may take hours for Mt. Gox to help you out.
At what point did you think you were dealing with a "normal, professional company" in Mt. Gox?
What did it for you?  Their over-the-top web design?  Advanced trading tools?  Sophisticated, deep market?

They're not Citibank.  Either they've taken off with the money and all of this is meant as a stall tactic, or (my guess) they're flogging their fingers off trying to completely overhaul their system.  If you think their responsiveness has been or is unacceptable, take your business to one of the "normal, professional" exchanges.

If bitcoin is the libertarian ideal, the exchanges fit right in.

Trust them because they seem trustworthy and "everyone" else does.

You're in charge of your own destiny out there, don't play with more than you can afford to lose is common advice.

Posting photos of the goods for sale with a piece of paper containing the forum name, your username and the date is a common practice in online sales to prove you've at least got the goods being advertised.

What brand?

Number of GPUs is certainly the biggest factor!  Nothing can touch the two-chips-on-one-card cards!
Number of shaders is how many simultaneous operations you can perform
Speed of core is how fast each one goes.

Clearly the last two work together to determine a cards potential hash rate.

Set that fan speed to 100 then see if it still locks up.  Then you can work on auto settings or lowering to more tolerable speeds.

I'm just about as helpless as the next guy in ubuntu, but you'll probably need to boot to a command line shell and re-initialize your X setup.
But that's about all the detail I can give you on it!  Try some google or search on the ubuntu forums.
I think your problem is that X doesn't see the video card it's accustomed to and it's not that good at adapting.

Be sure to try using the 11.6 catalyst drivers, they allow clock speeds outside of the displayed ranges.
If you let ubuntu install the ATI driver automatically, it's a bit of a mess to get the generic 11.6 driver to install.
About all I can offer on the topic was that even though I couldnt ever get the 11.6 to install properly, by the time I was done and went back to the driver installed by ubuntu, I was able to get bigger overclocks. 

I second the suggestion to turn that fan speed up or leave it on auto.
Are you overclocking the cards?  Leave the speeds stock, also.
It sounds similar to a crash mode I get on ubuntu from cards that are pushed too far, thermally/speed wise after a while.

Are you enabling overdrive on the adapter first when you try to do it form the command line?

aticonfig --od-enable --adapter=all

Then try your setclocks.

What brand(s) on the 5870s?

AMD very strongly recommends uninstalling before updating.