CMS Assessment Tool Crashes

I am trying to run the CMS assessment tool against a large MCMS site that is going to be migrated to MOSS 2007. The tool just won't analyse the code, it crashes with a "Stack Empty" error. This is the error from the CmsAssessmentTool.log file:

While calculating results: System.InvalidOperationException: Stack empty.
at System.Collections.Stack.Peek()
at Microsoft.ContentManagement.AssessmentTool.ILParser.ParsingClasses.CollectingParser.OnEnterMethod(String name, String[] attributes, TypeReference returnType, TypeReference ownerMethod, ArgData[] parameters)
at Microsoft.ContentManagement.AssessmentTool.ILParser.ParsingClasses.Parser.ParseMethodDecl()
at Microsoft.ContentManagement.AssessmentTool.ILParser.ParsingClasses.Parser.ParseDeclaration()
at Microsoft.ContentManagement.AssessmentTool.ILParser.ParsingClasses.Parser.ParseFile()
at Microsoft.ContentManagement.AssessmentTool.ILParser.ParsingClasses.CollectingParser.ParseFile()
at Microsoft.ContentManagement.AssessmentTool.AspNetProcessor.AspRepresentation.CmsTypeResolutionHelper.ResolveTypeNameByParsing(String ns, String className, DirectoryInfo binDirectory, String assemblyName, String sourceName)
at Microsoft.ContentManagement.AssessmentTool.AspNetProcessor.AspRepresentation.CmsTypeResolutionHelper.ResolveRealName(String ns, String className, DirectoryInfo binDirectory, String assemblyName, String sourceName)
at Microsoft.ContentManagement.AssessmentTool.AspNetProcessor.AspRepresentation.AspControl.RetrieveControlType()
at Microsoft.ContentManagement.AssessmentTool.AspNetProcessor.AspRepresentation.CmsPlaceholderControlSearchCriteria.Applies(AspControl control)
at Microsoft.ContentManagement.AssessmentTool.AspNetProcessor.AspRepresentation.AspElement.CollectPlaceholderControls(IControlSearchCriteria criteria)
at Microsoft.ContentManagement.AssessmentTool.AspNetProcessor.CodeAnalyzer.GenerateFirstXmlResultFile(ArrayList processedElements, MSILCollector collector, WebConfigAnalysis webConfigAnalyzer, Hashtable projectLineCounts, ArrayList projectFiles, ArrayList serviceElements, ArrayList skippedFiles)

Has anyone seen this before Is there a workaround I realize this is a beta product, but is there any way I can identify the piece of our code that is causing this and maybe eliminate it from the analysis Any suggestions would be most appreciated.

Dave