Error ASP.NET + Access

[Ascariz]

Buenos dias a todos.

Tengo un problema, de vez en cunado me da un error al conectar a la BBDD.
Error es este: me podeis dar alguna solucion.

Código:

Server Error in '/' Application.
--------------------------------------------------------------------------------

Unspecified error
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.OleDb.OleDbException: Unspecified error

Source Error:


Line 180:
Line 181:        Dim com As New OleDbCommand(sql, conexion)
Line 182:        conexion.Open()
Line 183:        Dim odr As OleDbDataReader
Line 184:        odr = com.ExecuteReader


Source File: 
Line: 182

Stack Trace:


[OleDbException (0x80004005): Unspecified error]
   System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString
constr, OleDbConnection connection) +969373
   System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions
options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection
owningObject) +86
   System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection
owningConnection, DbConnectionPoolGroup poolGroup) +29
   System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection
owningConnection) +4863644
   System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection
outerConnection, DbConnectionFactory connectionFactory) +117
   System.Data.OleDb.OleDbConnection.Open() +40
   _Default.Page_Load(Object sender, EventArgs e) in
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +50
   System.Web.UI.Page.ProcessRequestMain(Boolean
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627

[Ascariz]

Necesito un poquito de Ayuda..... Estoy desesperado........

Server Error in '/' Application.
--------------------------------------------------------------------------------

Unspecified error
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.OleDb.OleDbException: Unspecified error


Por que puede ser esto?????