Thanks. Those settings give me 0 WU and many HW errors on catalyst 13.12 under Linux.
Edit: To clarify, I am running Ubuntu 12.04 32 bit.
You have wrong kernel from sources (x13mod.cl = 31 KB), working kernel for 5850 and binary for windows is in my link (x13mod.cl = 281 KB).
Deleted old *.bin files, recompiled with the larger x13mod kernel, and it's giving me "Error -46: Creating Kernel from program. (clCreateKernel #name)" followed by a segmentation fault.