Found the problem. You have to edit the entry on the agenda screen. Long press it and option menu will pop up, you can edit it. If you go into the actual entry though, it is view only. It's ridiculous!!!
Okay, if I edit an event that is a day or two in the past, say I change the name, it moves it forward a day. I edited an event from 9/22, changed the name from Headset to Headsets. when I saved it now showed up on 9/23. did this for an event on 9/23, now it's on todays calendar.
edit, weird, now I can't reproduce this, yet I did it twice. Sorry.