2012-10-29 18:56:55: Listener for "gpu2": btcoxygen.com:8332 29/10/2012 18:56:55, checking for stratum...
2012-10-29 18:56:55: Listener for "Default": btcoxygen.com:8332 29/10/2012 18:56:55, checking for stratum...
2012-10-29 18:57:00: Listener for "gpu2": btcoxygen.com:8332 29/10/2012 18:57:00, no response to getwork, using as stratum
2012-10-29 18:57:00: Listener for "Default": btcoxygen.com:8332 29/10/2012 18:57:00, no response to getwork, using as stratum
2012-10-29 18:57:10: Listener for "gpu2": btcoxygen.com:8332 29/10/2012 18:57:10, Failed to subscribe
2012-10-29 18:57:10: Listener for "Default": btcoxygen.com:8332 29/10/2012 18:57:10, Failed to subscribe
2012-10-29 18:57:12: Listener for "gpu2": btcoxygen.com:8332 29/10/2012 18:57:12, IO errors - 1, tolerance 2
2012-10-29 18:57:12: Listener for "Default": btcoxygen.com:8332 29/10/2012 18:57:12, IO errors - 1, tolerance 2
what flags are you using in GUI Miner?