Curious problem this – I had a web part zone where all web parts being put in it would be displayed without their titles. Didn’t matter if you manually went and turned on the chrome to show a title – that setting never saved, and the web parts didn’t ever have a title.
After tracking through all the page’s code, I found that when I set the WebPartZone’s ID to be ‘Main’ then my web parts ceased functioning correctly; their titles disappeared. If I set the ID back to ‘Left’, then all was fine.
I don’t know why this happens, but certainly using a different ID for my zone fixes it. If anyone knows why this actually happens, please let me know.