GeneXus - Postgres y .net

Estoy trabajando con .net y una base de datos postgres (localhost) y me sucede algo raro. Si estoy desconectado de la red Internet (trabajar sin conexion a la red), funciona la aplicacion pero me abre solamente una transacción. Cuando quiero grabar un registro en una tabla no graba absolutamente nada. Si me conecto a la red, me salta el siguiente error.
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Server Error in '/services' Application.
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Configuration Error
Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: The located assembly's manifest definition with name 'GxClasses' does not match the assembly reference.

Source Error:

Line 38: <add verb="*" path="tconceptos_propiedades.aspx" type="GeneXus.Programs.tconceptos_propiedades,tconceptos_propiedades" />
Line 39: <add verb="*" path="tusuarios.aspx" type="GeneXus.Programs.tusuarios,tusuarios" />
Line 40: <add verb="*" path="hgx0020.aspx" type="GeneXus.Programs.hgx0020,hgx0020" />
Line 41: <add verb="*" path="hgx0030.aspx" type="GeneXus.Programs.hgx0030,hgx0030" />
Line 42: <add verb="*" path="hgx0050.aspx" type="GeneXus.Programs.hgx0050,hgx0050" />


Source File: C:\Inmobiliarias\DATA002\web\web.config Line: 40

Assembly Load Trace: The following information can be helpful to determine why the assembly 'GxClasses' could not be loaded.

=== Pre-bind state information ===
LOG: DisplayName = GxClasses, Version=1.0.0.0, Culture=neutral, PublicKeyToken=74ebdef9af814246
(Fully-specified)
LOG: Appbase = file:///C:/Inmobiliarias/DATA002/web
LOG: Initial PrivatePath = bin
Calling assembly : hgx0020, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null.
===

LOG: Publisher policy file is not found.
LOG: No redirect found in host configuration file (C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\aspnet.config).
LOG: Using machine configuration file from C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\config\machine.config.
LOG: Post-policy reference: GxClasses, Version=1.0.0.0, Culture=neutral, PublicKeyToken=74ebdef9af814246
LOG: Attempting download of new URL file:///C:/WINDOWS/Microsoft.NET/Framework/v1.1.4322/Temporary ASP.NET Files/services/a602d4ba/fcf02718/GxClasses.DLL.
LOG: Attempting download of new URL file:///C:/WINDOWS/Microsoft.NET/Framework/v1.1.4322/Temporary ASP.NET Files/services/a602d4ba/fcf02718/GxClasses/GxClasses.DLL.
LOG: Attempting download of new URL file:///C:/Inmobiliarias/DATA002/web/bin/GxClasses.DLL.
WRN: Comparing the assembly name resulted in the mismatch: Revision Number

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Version Information: Microsoft .NET Framework Version:1.1.4322.573; ASP.NET Version:1.1.4322.573

Alguien sabe como solucionarlo ????
EL sistema operativo es Win XP y el estoy trabajando con IIS...

Desde ya muchas gracias ...