I finally figured out the "network search..." problem
I installed softick PPP couple of days ago to connect my treo with PC, I noticed that I need to add a new network connection to do that. I don't know what the default services are, but mine are: cingular GPRS and media net and cingular CSD, and I have a customized service type for softick PPP, whenever I switched to that, and reseted the phone, it will not be able to find the network even though the signal bars are there and I could make and receive phone calls w/out a problem. and I swith the service to either cingular CSD or cingular GPRS "network search..." problem goes off.

Hope this is useful for those of you still got bothered by this prolem.