I presume that your ReportListX is the name of a subform control where subform2 is residing, and that you have the subform properly linked to the main form. In that case, I believe you need to have the syntax modified to

Forms!ProjectAdmin.ReportListX.Form!RecordSource = sqlstr

See the knowledge base article ACC: How to Refer to a Control on a Subform or Subreport for the details on referencing a subform. Note that if the code is running on an event from your main form, you can use the Me. prefix in place of Forms!ProjectAdmin.