Exactly what happens when you try? Are you using only the webmail interface and a browser to access the email?
Try clearing out your browser's cache/browsing history. When you have done that, close out the browser and re-start it in a fresh session. If that doesn't do it, then try using a different browser. You could also try just refreshing the page.
Dear Latoque, Thank you so nuch for the "cure" and I'll be sure to keep your quick response somewhere handy if I have the problem in the future. It worked like a charm. Bless you!