YahooMail and Firefox

[pasanjes]

When I use YahooMail in my Firefox, the messages do appear, but without their text in the "reading pane" below..And, they cannot be opened and read... As this works fine under InternetExplorer8, the simple question is: why does it no longer work under Firefox ? As long as I cannot find a solution to this problem, I'll have to switch from FF to IE8 each time I want to read and respond to Emails...which is quite annoying. Can anyone help ?
Thank you!