Strange automatic NIS process overload my CPU

Hello everyone.

For some time I have noticed that when I leave the computer idle, Norton 2011 will be put to work in a completely unknown process that disables the product interface. This process does not appear as a complete analysis, or any name, and can not be stopped once started.

The CPU is occupied by 80% by this process. I repeat, not an analysis of inactivity and no automatic optimization; norton2011 gives no name to this process.

I wonder what exactly and how to disable it so I would not leave the computer hindered.

My system:

Windows Vista Home Premium 32-bit SP2
Intel Pentium Dual Core 1.46 GHz
2.0 GB RAM
Mobile Intel 965 Express Chipset Family
NIS2011 18.5.0.125 is my only security software

Best regards!