I have a Thunderbolt with the same issue. The application causing the problem for me is VZ Navigator. I used Advanced Task Killer to kill this app and also went under, Settings>Applications>Manage Applications and did a "Force Stop" to kill this task. And it fixes it for about 30 minutes. Then I look and the dang application is running again. I emailed HTC and they told me to-- Please press Home > MENU and then tap Settings > Display and adjust the display timeout settings for your device. Soft reset your phone by powering it off, removing the battery, waiting ten seconds, and then reinserting the battery and restarting the device.
If your device continues to experience display timeout issues, I recommend you restore it to its factory default settings by performing a factory date reset. This will permanently erase all installed programs and data files on your phone; you will therefore want to first back up all files to your storage card or to a third party application from the Android Market. Use HTC Sync to back up Outlook contacts and calendar files, or Google Sync to back up your Google contacts and calendar. Calendar events are color-coded: green for Outlook, blue for Google, and orange for Exchange. You can back up text and picture messages by forwarding them to an email address. It will not affect files on your storage card.
To perform a factory data reset, please press Home > MENU and then tap Settings > SD & phone storage > Factory data reset > Reset phone > Erase everything.
If your device's issue persists, I respectfully recommend you contact your carrier for further assistance.
Wow, that is some answer. As if they didn't give a crap if they have an issue with their phone. "Sorry sir, just erase everything and start over. See if that will work."
