Memphis... Respectfully, The Slot Index thing IS a system issue and I too had this with my last phone not just the Hero, Last phone was a Palm Treo which required the same fix for ringer lag. Not the same commands, but the same fix, changing the Slot Index Cycle to a lower number.
Have you tried all the settings, like 1 instead of just 0? Also, have you reset it back to default and checked like you said to see if there was a difference in rings prior heard to cell ringing? I don't know, just making suggestions. Hope it works out for ya'. Did for me.
