Web application and ReportViewer contol - .rdlc rpt with many subreports within and parameter link. Possible???

Question

Before I trash a handful of rdlc reports created in VS2005 as .rdl's and then copy/pasted into folder as rdlc's in a VS2008 web application project, I will ask for information from subscribers to this site. 
Is it possible to display a parent rdlc report that contains several subreports that link to the parent report via 1 parameter who's value should be supplied by the parent reports parameter value??? I'm using VS2008, reportviewer control that uses a sqldatasource control configured to execute a stored procedure with 3 parameter values. One of these values becomes the parameter value for the subreports that it contains.
I keep getting messages "An error has occurred during report processing. Input string was not in a correct format."
Has anyone else developed a web app with local report processing and the parent report uses subreports with a linked parameter and gotten it to work?

thanks,
SMA