Sitebuilder Shutdown

I have a question. It seems that whener I am updating or adding new images or even just moving things around on my site pages, If I am on the Homestead sitebuilder for more than 20 to 30 minutes, it freezes up so I cannot save or publish to the web, so I have to close it and re-open it and sometimes re-edit what I already did, but this time hitting the 'Save' button every few seconds to make sure I don't lose my new changes. Any suggestions why this happens and what to do about to stop it from happening?
Thanks for your help!