Re-boot didn't work. Cleaning out Temporary ASP.NET Files.
Some additional info: Assembly Load Trace: The following information can be helpful to determine why the assembly 'Castle.DynamicProxy' could not be loaded. === Pre-bind state information === LOG: DisplayName = Castle.DynamicProxy, Version=1.0.3.0, Culture=neutral, PublicKeyToken=407dd0808d44fbdc (Fully-specified) LOG: Appbase = file:///C:/Web Services/TransmissionMonitor LOG: Initial PrivatePath = bin Calling assembly : IBatisNet.DataMapper, Version=1.2.0.0, Culture=neutral, PublicKeyToken=null. === LOG: Publisher policy file is not found. LOG: No redirect found in host configuration file (C:\WINNT\Microsoft.NET\Framework\v1.1.4322\aspnet.config). LOG: Using machine configuration file from C:\WINNT\Microsoft.NET\Framework\v1.1.4322\config\machine.config. LOG: Post-policy reference: Castle.DynamicProxy, Version=1.0.3.0, Culture=neutral, PublicKeyToken=407dd0808d44fbdc LOG: Attempting download of new URL file:///C:/WINNT/Microsoft.NET/Framework/v1.1.4322/Temporary ASP.NET Files/transmissionmonitor/f9c49154/62b14345/Castle.DynamicProxy.DLL. LOG: Attempting download of new URL file:///C:/WINNT/Microsoft.NET/Framework/v1.1.4322/Temporary ASP.NET Files/transmissionmonitor/f9c49154/62b14345/Castle.DynamicProxy/Castle.DynamicProxy.DLL. LOG: Attempting download of new URL file:///C:/Web Services/TransmissionMonitor/bin/Castle.DynamicProxy.DLL. WRN: Comparing the assembly name resulted in the mismatch: Minor Version Stack Trace: [FileLoadException: The located assembly's manifest definition with name 'Castle.DynamicProxy' does not match the assembly reference.] IBatisNet.DataMapper.MappedStatements.MappedStatement.SetObjectProperty(RequestScope request, ResultMap resultMap, ResultProperty mapping, Object& target, IDataReader reader) +0 IBatisNet.DataMapper.MappedStatements.MappedStatement.ApplyResultMap(RequestScope request, IDataReader reader, Object resultObject) IBatisNet.DataMapper.MappedStatements.MappedStatement.RunQueryForList(RequestScope request, IDalSession session, Object parameterObject, Int32 skipResults, Int32 maxResults, RowDelegate rowDelegate) IBatisNet.DataMapper.MappedStatements.MappedStatement.ExecuteQueryForList(IDalSession session, Object parameterObject, Int32 skipResults, Int32 maxResults) IBatisNet.DataMapper.MappedStatements.MappedStatement.ExecuteQueryForList(IDalSession session, Object parameterObject) IBatisNet.DataMapper.SqlMapper.QueryForList(String statementName, Object parameterObject) USR.DAL.Transmission.LookupDALC.ReadAll(String objectName) in C:\Web Services\eRecording\DAL\Transmission\LookupDALC.cs:16 USR.BLL.Transmission.TransmissionTypeFacade.ReadAll() in C:\Web Services\eRecording\BLL\Transmission\TransmissionTypeFacade.cs:26 USR.TransmissionMonitor.Controls.Header.Page_Load(Object sender, EventArgs e) in C:\Web Services\TransmissionMonitor\Controls\Header.ascx.cs:23 System.Web.UI.Control.OnLoad(EventArgs e) System.Web.UI.Control.LoadRecursive() System.Web.UI.Control.LoadRecursive() System.Web.UI.Control.LoadRecursive() System.Web.UI.Page.ProcessRequestMain()