with scrypt only, 3.1.1 causes an error, regardless of pool.
cgminer 3.1.1 log
[2013-05-15 07:06:23] Started cgminer 3.1.1
[2013-05-15 07:06:23] CL Platform 0 vendor: Advanced Micro Devices, Inc.
[2013-05-15 07:06:23] CL Platform 0 name: AMD Accelerated Parallel Processing
[2013-05-15 07:06:23] CL Platform 0 version: OpenCL 1.1 AMD-APP-SDK-v2.5 (793.1)
[2013-05-15 07:06:23] Platform 0 devices: 1
[2013-05-15 07:06:23] 0 Cypress
[2013-05-15 07:06:23] GPU 0 ATI Radeon HD 5800 Series hardware monitoring enabled
[2013-05-15 07:06:24] Init GPU thread 0 GPU 0 virtual GPU 0
[2013-05-15 07:06:24] CL Platform vendor: Advanced Micro Devices, Inc.
[2013-05-15 07:06:24] CL Platform name: AMD Accelerated Parallel Processing
[2013-05-15 07:06:24] CL Platform version: OpenCL 1.1 AMD-APP-SDK-v2.5 (793.1)
[2013-05-15 07:06:24] List of devices:
[2013-05-15 07:06:24] 0 Cypress
[2013-05-15 07:06:24] Selected 0: Cypress
[2013-05-15 07:06:24] Selecting scrypt kernel
[2013-05-15 07:06:32] Initialising kernel scrypt130511.cl with bitalign, 1 vectors and worksize 256
[2013-05-15 07:06:32] initCl() finished. Found Cypress
[2013-05-15 07:06:32] 1 gpu miner threads started
[2013-05-15 07:06:32] Network diff set to 39.7M
[2013-05-15 07:06:32] New block: f377e4dce13e0a7b... diff 39.7M
[2013-05-15 07:06:33] New best share: 1
[2013-05-15 07:06:33] GPU0: invalid nonce - HW error
[2013-05-15 07:06:34] GPU0: invalid nonce - HW error
^C [2013-05-15 07:06:34] Received kill message
cgminer 3.1.0 works fine
[2013-05-15 07:05:05] Started cgminer 3.1.0
[2013-05-15 07:05:05] CL Platform 0 vendor: Advanced Micro Devices, Inc.
[2013-05-15 07:05:05] CL Platform 0 name: AMD Accelerated Parallel Processing
[2013-05-15 07:05:05] CL Platform 0 version: OpenCL 1.1 AMD-APP-SDK-v2.5 (793.1)
[2013-05-15 07:05:05] Platform 0 devices: 1
[2013-05-15 07:05:05] 0 Cypress
[2013-05-15 07:05:05] GPU 0 ATI Radeon HD 5800 Series hardware monitoring enabled
[2013-05-15 07:05:06] Init GPU thread 0 GPU 0 virtual GPU 0
[2013-05-15 07:05:06] CL Platform vendor: Advanced Micro Devices, Inc.
[2013-05-15 07:05:06] CL Platform name: AMD Accelerated Parallel Processing
[2013-05-15 07:05:06] CL Platform version: OpenCL 1.1 AMD-APP-SDK-v2.5 (793.1)
[2013-05-15 07:05:06] List of devices:
[2013-05-15 07:05:06] 0 Cypress
[2013-05-15 07:05:06] Selected 0: Cypress
[2013-05-15 07:05:07] Selecting scrypt kernel
[2013-05-15 07:05:07] Initialising kernel scrypt130302.cl with bitalign, 1 vectors and worksize 256
[2013-05-15 07:05:07] initCl() finished. Found Cypress
[2013-05-15 07:05:07] 1 gpu miner threads started
[2013-05-15 07:05:07] Network diff set to 39.7M
[2013-05-15 07:05:07] New block: f377e4dce13e0a7b... diff 39.7M
[2013-05-15 07:05:09] Setting GPU 0 fan percentage to 51
[2013-05-15 07:05:11] Received kill message
[2013-05-15 07:05:11] Thread 0 being disabled