Detail members can only contain static inner members.

I am developing an RDL in SSRS 2008 and am trying to move a subreport table directly into a main report so that I instead run this subreport in the same stored proc as my main report.  However, I'm having trouble hooking this up.  I got the stored proc to run successfully.  But now when I try to copy this table into the main report I get the following errors:

Error	1	[rsInvalidDetailDataGrouping] The tablix ‘table2’ has a detail member with inner members. Detail members can only contain static inner members.	\\operations\userfiles\R15D\Documents\Visual Studio 2008\Projects\Test\Test2\DischargePlan.rdl	0	0	

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Report item expressions can only refer to fields within the current dataset scope or, if inside an aggregate, the specified dataset scope

How do I do this?  I have tried various workarounds I found on the internet but none have worked.  I have tried moving the table into the group level and deleting the details grouping.  I have removed sorting elements, etc.  But the only way I got this error to disappear is to delete all of the groupings for this table and all textbox values.