problem with references

Hi, I'm trying to recompile my CS functions, and my references look like this at the moment:

using System;
using System.Collections.Generic;
//using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Media;
using System.Drawing;
using System.Windows.Forms;
using System.Threading;
using System.IO;
using Bentley.GenerativeComponents.GeneralPurpose;
using Bentley.GenerativeComponents.GCScript;
using Bentley.GenerativeComponents.GCScript.GCTypes;
using Bentley.GenerativeComponents.GCScript.Namescopes;
using Bentley.Interop.MicroStationDGN;
using Bentley.MicroStation;

The last line is the important one, I'm importing Bentley.MicroStation, but the dll in the assemblies folder is bentley.MicroStation - this doesn't seem to cause a problem in visual studio.

When I try to run it in GC i get the following compiler error:

c:\ProgramData\Bentley\08.11.08.202\GenerativeComponents\WorkSpace\Projects\Examples\GC_Default\Features\NP_Functions1.06i.cs(85,15): error CS0234: The type or namespace name 'MicroStation' does not exist in the namespace 'Bentley' (are you missing an assembly reference?)

Which looks a bit fishy. Any idea what's going on?