In tracking and experiencing some of the strange Evo issues of excessive data use, intermittent short battery life and spontaneous reboots, a common culprit has become the leading suspect: Facebook for HTC Sense, particularly its contact/people syncing capability. It appears to get stuck downloading like crazy.
I am suspicious that this massive data demand can possibly cause all of those issues for various reasons. So if you are having any of these issues, try turning off your automatic facebook syncing (in settings > accounts & sync > facebook for HTC sense > uncheck sync contacts and sync live feed). IMO there's no real need to sync live feed (friend stream and the sense facebook widget suck anyway) and contacts can be manually synced as needed.
Note about the reboot issue: The general fix has been to turn ON settings > wireless & networks > always-on mobile, if you had turned it off for battery reasons. In lieu of this, people having reboots, please test turning off facebook sync first and seeing if that helps (and pls report).
For some background on these issues, here are some previous threads:
http://androidforums.com/htc-evo-4g/103811-what-my-phone-downloading.html
http://androidforums.com/support-troubleshooting-evo-4g/96897-evo-rebooting-its-own.html
http://androidforums.com/htc-evo-4g/107468-so-my-wifes-phone-somehow-used-720-mb-data-one-day.html
http://androidforums.com/htc-evo-4g/98901-its-been-week-how-much-data-have-you-used.html
http://androidforums.com/support-tr...essages-wont-scroll-up-snaps-back-newest.html
EVO 4G continously downloading Facebook photos - possibly from Friendstream - xda-developers
Evo 4g battery saving tip - get rid of the people widget - xda-developers
Update: This rumored update may address this very issue: EVO 4G to get a software update on June 28th? Boy Genius Report
I am suspicious that this massive data demand can possibly cause all of those issues for various reasons. So if you are having any of these issues, try turning off your automatic facebook syncing (in settings > accounts & sync > facebook for HTC sense > uncheck sync contacts and sync live feed). IMO there's no real need to sync live feed (friend stream and the sense facebook widget suck anyway) and contacts can be manually synced as needed.
Note about the reboot issue: The general fix has been to turn ON settings > wireless & networks > always-on mobile, if you had turned it off for battery reasons. In lieu of this, people having reboots, please test turning off facebook sync first and seeing if that helps (and pls report).
For some background on these issues, here are some previous threads:
http://androidforums.com/htc-evo-4g/103811-what-my-phone-downloading.html
http://androidforums.com/support-troubleshooting-evo-4g/96897-evo-rebooting-its-own.html
http://androidforums.com/htc-evo-4g/107468-so-my-wifes-phone-somehow-used-720-mb-data-one-day.html
http://androidforums.com/htc-evo-4g/98901-its-been-week-how-much-data-have-you-used.html
http://androidforums.com/support-tr...essages-wont-scroll-up-snaps-back-newest.html
EVO 4G continously downloading Facebook photos - possibly from Friendstream - xda-developers
Evo 4g battery saving tip - get rid of the people widget - xda-developers
Update: This rumored update may address this very issue: EVO 4G to get a software update on June 28th? Boy Genius Report