Device #1: WARNING! Kernel exec timeout is not disabled, it might cause you errors of

[wulong]

I have installed the bumblebee on ubuntu 13.04.
when i run sudo optirun sh cudaExample400.sh
it will be:
Hashes: 1 total, 1 unique salts, 1 unique digests
Bitmaps: 8 bits, 256 entries, 0x000000ff mask, 1024 bytes
Rules: 1
Workload: 128 loops, 80 accel
Watchdog: Temperature abort trigger set to 90c
Watchdog: Temperature retain trigger set to 80c
Device #1: GeForce GT 620M, 1023MB, 1250Mhz, 2MCU
Device #1: WARNING! Kernel exec timeout is not disabled, it might cause you errors of code 702
ERROR: cuModuleLoad() 209

How can I do?