Because ProtoShare is a web-based application that uses HTML, CSS, and JavaScript, its performance is heavily dependent on your browser. We made great strides in the app's performance with ProtoShare 5 (released Feb. 28, 2011) - it is quite responsive and feels like a desktop app in many cases.
However, if you feel performance is lagging, try disabling the following browser add-ons: Skype, Firebug, Web Developer, IE Developer Toolbar, and IE Script Debugger.
Another way to increase performance is to upgrade your browser to the latest version: Chrome, Safari, or Firefox.
It's also important to make sure you have an acceptable and dependable Internet connection.