Motorola Q

Long time lurker, first time poster. I use my Q at work to access a secured website, which I had no problem accessing in the past. But a few days ago a message popped up before the login sceen that said "Information you exchange on this site cannot be viewed or changed by others. However, the name, date, or issuing authority for the sites security certificate is invalid. Do you want to proceed. Yes/No." When I login, a message reads "Could not login, please try again later." Could this be a security issue with my Q or should I contact the website. I friend who uses another pda has no problems. Any type of help would be greatly appreciated. Thanks.