I have replaced my original sim card twice already. I still get the 'no sim card' error about every 2 days and need to remove it and reseat it. Verizon tech told me that HTC is working on a firmware fix for this as it is a software bug and not related to the physical sim card. All that the reboot, airplane mode toggle, or remove/reseat is doing is forcing the software to reauthorize the sim card details on their network to validate the service. HTC requested the details for my phone (IMEI, serial number, etc.) and they will push a fix down to me once they have one. Probably before Verizon can test and package one up. They are well aware of the issue and asked me to try to run the phone in global mode instead of LTE/CDMA. This did not make any difference and I kept getting messages that my phone was in global mode and I could be susceptible to roaming charges. Needless to say, it is back in LTE/CDMA as I wait for a fix.