C# linq to sql designer

Question

In a C# 2008 desktop application that uses linq to sql to connect to a sql server 2008 r2 database, I am getting an error message. The error message did not occur when I was executing the application on my own workstation and I am  pointing to a test database where I have sa priviledges. This database also has 3 new triggers on one particular database. This error occurs when I am pointing to a different test database.

I am getting the following error:
2013-02-04 16:13:58.5695|ERROR|sampleclient.Sample|Error Processing --> Specified cast is not valid.
2013-02-04 16:13:58.5695|ERROR|sampleclient.Sample|************* Stack Trace *******************
2013-02-04 16:13:58.5851|ERROR|sampleclient.Sample|   at System.Data.Linq.SqlClient.SqlProvider.Execute(Expression query, QueryInfo queryInfo, IObjectReaderFactory factory, Object[] parentArgs, Object[] userArgs, ICompiledSubQuery[] subQueries, Object lastResult)
   at System.Data.Linq.SqlClient.SqlProvider.ExecuteAll(Expression query, QueryInfo[] queryInfos, IObjectReaderFactory factory, Object[] userArguments, ICompiledSubQuery[] subQueries)
   at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query)
   at System.Data.Linq.DataQuery`1.System.Linq.IQueryProvider.Execute[S](Expression expression)
   at System.Linq.Queryable.SingleOrDefault[TSource](IQueryable`1 source)

Can you tell me if my problem can be permissions on the database? If so can you tell me what type of permission I need to give to the triggers?