Change Default Zoom Setting For Reports Viewed On Report Manager Web Site

I've tried changing the default zoom setting by editing the RSReportServer.config file to include

<Configuration>

<DeviceInfo>

<Zoom>Page Width</Zoom>
</DeviceInfo>
</Configuration>
under the

<Render>

<Extension Name = "HTML4.0" etc.
However, all reports still show up with the zoom setting at 100% on the toolbar.
I stop and restart the Report Server Service and it comes up OK so I know my XML syntax is cool. What am I doing wrong?

This is on a 2005 Report Server. Reports are built in VS2005 Report Designer and deployed to the Report Server directly. Reports are accessed via IE7 browser.