Just in case you don't realize, the maximum number of simultaneous downloads in IE 7. This is the case even before IE 7 days. The fix to this inconvenience has remained the same and applicable to all versions of IE.
Refer to below link for the fix.
http://vistarewired.com/2007/04/16/increase-the-number-of-simultaneous-downloads-in-internet-explorer-7/
