TCP/IP protocol is mismatched

[DEVR3311]

We have installed MGE 2011 with IIS 6.0 on Windows Server 2003. We made MGPs for our MGE 2009 repository and successfully imported them into 2011. 

My maps load up in 2011 and programmatically I can make a map object. Several methods of the map object work, specifically: 
- GetResourceId() 
- GetResourceType() 
- GetMapDefinition() 

However, when I try: 
MgLayerCollection layerCollection = map.GetLayers(); 

A stream IO exception occurred. 
The TCP/IP protocol is mismatched between the Server and Web Extensions.  Please install the same version of Server and Web Extensions. 

Even when I make a new web layout and new map and add a new layer from a new data source I get this exception. 

Any suggestions? 

Thanks