Need better workaround for hidden prompt without read-only behavior

I have many reports that have a parameter in them which I want to default to NULL and not show (plus other parameters I do want to show). If I leave the prompt field empty, I get the read-only error. The workaround has been to have the prompt field contain a single space, which works well as far as producing the behavior I want. However, every time you open the report in the designer, it automatically removes the space. What is a better solution?

When you clear the prompt string in Report Manager, make sure you do not check the prompt user flag.

The parameter values in the server override the designer parameter values. So even though the prompt string is back, it will still be hidden on the server.

In SQL 2005, we have made this behavor more clear.

|||I am not clearing the prompt string in Report Manager, I am doing so in the designer. These are reports that get installed at customer production sites by basically importing the rdl through a utility built into our software. I do not have access to maintaining the reports through report manager. Any suggestions?|||You would need to write in your iinstallation script that published the report to clear out the prompt string. The call is SetReportParameters.

Again, this is an RDL property in SQL 2005.sql