I'm not sure did i understood what you ment as english is not my main language, but here is cap of guiminer running:

It's because OpenCL 2.2 and higher is broken if you have more than 1 GPU.

So only downgrading to OpenCL 2.1 would fix this?

Doh!

I'd like to Mine on my CPU as I've got 8 threads sitting idle but it doesn't show up under the device's tab.

Is this an OpenCL problem?

well, I tried installing 10.11 + SDK 2.1, but it's a no go. What happens is gui miner complains that there is no valid OpenCL devices in the system. So I went to catalyst 11.4 which works and there is no 100% cpu usage with 1 miner (one card) but when the second one comes into the picture it's 100% all over again..

Am I the only one that could not get SDK 2.1 working on a 5870? Am I doing something wrong here? Does 2.1 even support the 5000 series?

Hmm, ok I shall give that a shot. So you're saying i should install 10.11 without the opencl drivers and then install 2.1 sdk separately..right?

Well that works and I've done that in the past, but 10.11 does NOT come with SDK Stream 2.1! It comes with 2.2. 

Maybe there is an unofficial drivers package that contains 2.1?

Yeah, I'll figure it out. At the moment it's not a big deal as there isn't much of a performance difference between 2.1 and 2.2 from what I hear, and using 2.2 on just ONE card does not cause that 100% cpu load issue. When I get my dummy vga plug I'm going to activate the second card so at that point I will look into making 2.1 work somehow. I'm thinking I'll wipe all the drivers away..install 10.1 with only the catalyst control panel and the video drivers and then install 2.1 standalone.

Something about that last GUI miner beta version:

KIV implement not only support for new poclbm, but  also multilanguage support.
To add your own language you just need to edit  file guiminer_ru.po, save it in 8 utf (without BOM) coding and run po_to_mo.exe (in parent directory). Then choose russian in language menu and restart GUI miner for test.
Don`t forget to send KIV  your version of guiminer_ru.po with reminder of what language you use. Than he will be able to add that new language version in language menu in next upcoming relise.
 Structure of guiminer_ru.po file is clear, i`m belive you will not need any instructions when you see it. Just change russian strings on your own.

Status of that multylanguage version is now beta, but very close to perfection. KIV is aware of some missed strings and will deal with them soon. And he is damnn fast !
Here is  last  updated version of russian version of guiminer_ru.po.:

http://narod.ru/disk/11566178001/guiminer_ru.zip.html