Wouldn't you know it, it works fine with SDK 2.1
![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif)
I used to have the same problem, and SDK 2.1 does indeed fix it
![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif)
The driver version is 10.12 as it is the latest that works on Gentoo, with Linux kernel 2.6.37.4.
I guess I was reluctant to try this SDK, since 2.2 worked much better with HD5570 (also using an older version of poclbm), but a few Mhash/s is not a bad price for getting the full setup to work.
As a nice bonus, CPU load is way down. With SDK 2.2, each miner consumed 100% CPU, but now it is barely noticeable.