WAS 6.30 stopped unexpectedly

I have installed a WAS 6.30 central instance on my desktop PC (Win2K Prof). However, I found that the J2EE server will be stopped a certain time automatically. When I look at the syslog in the SAP console, there will an error message "Operating system call recv failed (error no. 10054)". Do anybody have experience on this, and any advice on how to fix this?

Thanks. Clarence