Although my phone now doesn't have the "stuck in 1X" problem (at least for the last week or so), here's a response I received from HTC. At least they respond, unlike VZW.
"
Thank you for contacting HTC Technical Assistance Center. I apologize for the length of time it took me to respond to your email. I understand how frustrating it can be when your device switched from 3G to 1X without giving a command to do so. I will be happy to address this problem.
Go on your Imagio to Start> Settings> All Settings> Personal> Phone> Click on the CDMA Services Tab. Then you will need to highlight Network Services and hit get settings. When you have hit get settings you can toggle back and forth between the preferences to see if you can gain a better signal. If these steps are unable to resolve your issue then you will need to contact Verizon and have them trouble shoot the network on your device.
Thank you for contacting HTC today I hope I have addressed all your needs and concerns today. If you need any further assistance please feel free to reply to my email. Check out www.htc.com for any information about your device. Be sure to check out our online customer satisfaction survey located at http://survey.htc.com/worldwide and www.htcwiki.com."