Custom Renderer in SharePoint integrated mode

We have been successful in creating a custom Excel Renderer that works very well on a server configured for SSRS Native mode. However we have another server that is configured to work in SSRS integrated mode that we can not get this custom renderer to work properly. The steps we follow are:

After the report results are displayed we select Actions -> Export -> Excel Custom . So I can see the name of our custom rendering type. After a very short amount of time (no more than a second or 2) I get a frame that says: an unexpected error has occurred. Here is the URL of the web site:

http://sharepointserver/sites/BI/Reports/Reserved.ReportViewerWebPart.axd?ReportSession=2jqe4e45sm0sze553avovv55&ControlID=5c4fbb59def64efdac050393cd3fb338&Culture=1033&UICulture=1033&ReportStack=1&OpType=Export&FileName=edi001&ContentDisposition=OnlyHtmlInline&Format=CUSTOM_RENDERER

Is there anything that has to be done differently to get a custom renderer to work in SharePoint integrated mode?

Note: here is the article we followed to initially create the renderer that will work in SSRS native mode:

http://msdn.microsoft.com/msdnmag/issues/05/02/CustomRenderers/

Any help would be appreciated, thanks.

I have had the same problem, and have not found any hints yet on how to get a custom renderer to work. I check the supported/unsupported feature list for Integrated SSRS, and there is no mention there that the feature is not available, so am holding out hope that it is something simple.

-cg