Not enough memory message

I have been using Smart FTP with great ease up until recently. We have a calendar page on our website that I need to update from time to time. When I have tried to do so over the past couple months, I get a message which says that I have "Not enough memory to complete this operation." Is this a problem with Smart FTP or with my computer? I am not having any memory problems any time other than when I am trying to update this particular page. Any suggestions on what I can do to fix the problem?