Thanks. Everything is stock on the phone. The Calendar is checked for syncing. My Epic was set to 'All Calendars', which I changed to NOT include the 'My calendar' account. (gmail was already set to 'default'.) I did also find a suggestion in one of my Google searches that suggested deleting the Calendar Storage under Manage Applications (which I did) and letting the phone re-sync. I'm not sure why, but it now seems to be syncing OK.
If the problem returns, I will try the rest of your suggestion to power cycle and (if needed) uninstall and reinstall my gmail account.
Thanks.