ajax loaded content can be lost with slow internet connection

In the QT issue queue there are some issues about losing ajax loaded content. One reason could be the slow internet connection. I can reproduce the problem on the QT demo site.
Sometimes I see the progress bar without animation, sometimes the progress bar does not stop, sometimes I see empty tabs, sometimes it shows me an error about ajax views.
When I reload the page after my browser cached some of the data (or the site cached the data?) then the quicktabs works better. The most problematic tabs are the 2 large views.

I don't know how this could be improved, but maybe someone else will have some tips or ideas..