LinkTarget not working

I have tried from every angle to get rc:LinkTarget=_blank to work, but it won't.  Is there something I'm missing?  Here is a sample of what I'm doing.

http://[server]/ReportServer?/[reportname]&rs:Command=Render&rc:Format=HTML4.0&rc:LinkTarget=_blank

After going to this URL, as I understand it, the LinkTarget should cause all hyperlinks in the report to open in a new window.  Unfortunately, it continues to open all links in the same browser window.

Any help is appreciated.