Ever since I upgraded to 2.1 my hero will not ring. I've checked:
ringer volume
default ringtone
turned off/on airplane mode
turned off/on mobile network
turned on/off DDTM
turned off call forwarding
loaded HTC's 2.1 then Sprint's version
hard reboot/removed battery

I'm also noticing that I keep getting new network notification icons and when I check it says can't detect my current time zone. Weather app occasionally loses my current location as well.

Calls out work, and I get beeps when new gmails are received. But sucker refuses to ring. And it's not ring lag which others have, my landline will ring 5 time before going to Hero VM; not a peep out of the phone.