Mulitple split downloading
Some web servers do not allow files to be requested from midway through the file (range requests). When you are downloading a file from a server such as this the file will be downloaded using only one split.
If you PM me the link you are trying to download I will take a look to see if the server supports multi-split downloads.
Also sometimes if you are accessing the internet through a proxy server it may be possible that your proxy server does not support this functionality.
The final reason multiple splits may not be started is if the file you are downloading is small, DownloadStudio may select a more optimal number of splits to use.
Downloading from a streaming web server
Thanks for the url, I have taken a look at the web site. The reason why only one connection is allowed is that the video files are being served by a streaming media server.
Download managers cannot download these audio and video streams in the conventional way and Internet browsers and Windows media player cannot save these files to disk.
The DownloadStudio engine can download these files by streaming the content into a file. However as you have discovered only one split can be used for the download. Also it is not possible for DownloadStudio to resume a stopped download from a streaming media server.
By the way, here is the url I tried.
http://lang.stanford.edu/courses/aa2...aa240b-300.wmv
If you open the add job dialog in DownloadStudio, then paste this url in, and click Check Url, it will tell you the mime-type is "video/x-ms-wvx". This mime-type from the server tells us that it is a streaming window media file.