New parameter values don't show up for subreport when prompted

[suefhmis]

I've created a report which contains a subreport. Both reports have a parameter for the company name, and when refreshing the report data, the user must select the company name for both reports.
The main report's company name parameter is working fine. We added two new companies which didn't appear in the database I used to create the report. The two new company names show up in the drop-down list and either can be selected. The problem is with the sub-report. We went into the parameter definition in the sub-report and added the two new companies. They appear in the list of values. They don't, however, appear in the drop-down list when the user refreshes the report data and prompts for new parameter values! I've checked that all of the parameter definitions for the sub-report are the same as the main report. We deleted the two new companies, saved and closed the report, then re-opened the report and re-added the two new companies. No success.
The select expert is based on the company name being equal to the parameter field results.
Can anyone tell me why the new company names don't show up for the sub-report parameter?
Thanks!