ASP.NET MVC2 C#, Linq to SQL and web servers on Distributed File System

This question might/might not be related to programming but there is a huge number of programmers that might know what it is.

We have published ASP.NET MVC2 web application that uses Linq on the web server with IIS 7.5. This web application is automatically copied and served by 2 other servers thanks to Distributed File System set on all 3 servers开发者_JAVA百科. So in total there are 3 web servers on 3 different machines with load balancer configured.

Now with this configuration our web application does some weird stuff as processing transaction where there are two inserts to two tables and data is inserted only into one table or it does simple select by id (which is primary key) and returns more than one record. Also there are some conversion problems and others.

The problem appears only when there is a huge amount of visitors hitting the website. Otherwise is fine. The very curious thing is when there is only one server switched on and the other 2 are shut down all works fine(bit slower) even with huge volume of users(stress test). No errors no exceptions.

Also we run stress test on the static page (which doesn't retrieve any data form db) with all 3 servers on and it also works.

Has anyone else had this issue?

For the web application we use C# Asp.Net MVC2, repository pattern, linq to sql Server: MS Windows 2008 R2, MS SQL 2008 R2