AE版本：9.2 sp4
报错的内容：
The type 'ESRI.ArcGIS.MapControl.IMapControlEvents2_OnOleDropEventHandler' exists in both 'e:\Program Files\ArcGIS\DotNet\ESRI.ArcGIS.MapControl.dll' and 'e:\ProgramFiles\ArcGIS\DotNet\ESRI.ArcGIS.AxMapControl.dll'
解决方法：
1. In VS.NET 2005, go to your project's References folder in Solution Explorer. Select ESRI.ArcGIS.AxMapControl or ESRI.ArcGIS.MapControl. In the Properties Pane, change Aliases from global to global, MapControlAlias.
将AxMapControl，MapControl都加入到引用中，修改ESRI.ArcGis.AxMapControl引用的属性，修改其Aliases(别名)由"global" to "global, MapControlAlias";
2. In your code at the first line in the file add: extern alias MapControlAlias;
在其他命名空间之前添加extern alias MapControlAlias;
3. Add alias to your ambiguous call. Ex. this.axMapControl1.OnMouseMove += new MapControlAlias::ESRI.ArcGIS.MapControl.IMapControlEvents2_OnMouseMoveEventHandler(this.axMapControl1_OnMouseMove);
在冲突的地方，加上别名::想要调用的对象
This should work, don't worry about trying to do commandline /references as I couldn't figure it out, but the Properties Alias worked.
修改后，如下：
引用代码：
extern alias MapControlAlias;
using DevExpress.XtraEditors;
using DevExpress.XtraEditors.Controls;
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.DataSourcesFile;
using ESRI.ArcGIS.DataSourcesRaster;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.Geodatabase;
类中代码：
this.axMapControl1.OnMouseMove += new MapControlAlias::ESRI.ArcGIS.MapControl.IMapControlEvents2_OnMouseMoveEventHandler(this.axMapControl1_OnMouseMove);
this.axMapControl1.OnAfterDraw += new MapControlAlias::ESRI.ArcGIS.MapControl.IMapControlEvents2_OnAfterDrawEventHandler(this.axMapControl1_OnAfterDraw);
来源于：http://forums.esri.com/thread.asp?c=159&f=1707&t=171978&mc=6