Switching Between Tabs Sluggish

Switching between tabs is not as smooth as I would like it to be. Every time I click on a tab, the "loading" dialog shows briefly and the images on the tabs (pencil icon and the "close" x) must load.

Is Zoho retrieving the document from the database every time a tab is clicked? Why not keep the open documents on the client end and retrieve it locally when switching between tabs. That would be much faster. AJAX is fun, but I think unnecessary server requests should be kept to a minimum

Is the pencil icon and closing "x" images being retrieved from the server each time a tab is clicked? It seems like those should only be loaded onto the client once. Personally I think both images are unnecessary. The pencil icon is not necessary to show which tab is active. A simple color difference should suffice. The "x" image could be implemented as text instead.

Overall, I like Zoho. I'm beginning to use Zoho more than Word. It's nice to know that I can work from any computer.