SSRS report expressions not being evaluated when inside an MVC3 IIS6 C# project

In my MVC3 project I wanted to add reports, so I used SSRS local report rdlc (Microsoft Reporting) by creating a sub folder and putting the .aspx web viewer and rdlc in it. All was well until I tried expressions that had any sort of script functions in. They were not being evaluated and returning #Error (Even simple things like Len etc) wherever in the report I put them (header, body footer etc).

I am using an objectDatasource returning int values, Server 2003 SP2(hence IIS6) and vs2010 SP1 (Required by MVC3 package deployment).

So far I have worked out that

1) If I cre开发者_JAVA技巧ate a standard WEB project(NOT MVC3), then the expressions are evaluated.

2) If I use an MVC3 website on Server2008 (IIS7) then that works

I suspect that the IIS wildcard and gumph required to get MVC3 working with IIS6 is to blame, and am wondering if anyone else can shed light on this