2 days ago I've edited some descriptions using several browserwindows. After sending them back to the server several descriptions are mixed-up. Even two came up with exchanged title lines (even tough I didn't touch the title).

I expect the server has a serious problem with multitasking if the same user interacts with several processes, i.e. browserwindows (often the case if Ajax is used). This may lead to problems even while uploading a package and communicating with the server in another browserwindow (i.e. requesting other pages while the upload is in progress).