Just returned from a Cingular Authorized dealer with new SIM card. No more issues with "Insert SIM Card." They knew what I needed before I asked when they saw my phone, a new SIM. Many of these Samsungs have problems because they don't work with the old SIM cards. Free of charge. The phone works well for the average user. I just wanted a phone to talk on and was not necessarily concerned about all the bells and whistles. Also, my Plantronics Voyager 510 bluetooth works very well with this phone. I can go nearly 2 days with moderate usage without using charging the phone; longer if using the bluetooth. Nice phone!