System.AccessViolationException when launching MS Project in German Win7 OS

I have an application to launch MS Project application. The following piece of code is written to launch MS Project

Dim prjApp As MSProject.Application = Nothing
Dim iCount As Integer = 1
Dim strException As String = String.Empty
MessageFilter.Register()
While iCount <= 10
Try
prjApp = New MSProject.Application ' Exception is thrown is here
frmStart.WriteLog("modProject.vb: CreateProjectFile -> MS Project created in " & iCount.ToString() & " attempt")
Exit While
Catch ex As Exception
strException = ex.ToString()
System.Threading.Thread.Sleep(2000)
iCount += 1
End Try
End While
MessageFilter.Revoke()

If prjApp Is Nothing Then
frmStart.WriteLog("modProject.vb: CreateProjectFile -> Exit - Exception: " & strException)
MessageBox.Show("Exception while opening MS Project is: " + strException, "Error while opening MS Project", MessageBoxButtons.OK, MessageBoxIcon.Error)
Exit Sub
End If

The above piece of code works well in XP system(English and German) and Win7 English. But there is an exception on Win 7 German system. The exception is as follows:
Exception: System.AccessViolationException: Es wurde versucht, im geschützten Speicher zu lesen oder zu schreiben. Dies ist häufig ein Hinweis darauf, dass anderer Speicher beschädigt ist.

Meaning as:
An attempt was made to read or write protected memory. This is often an indication that other memory is corrupt.

Exception is thrown at the following line;
prjApp = New MSProject.Application

We have same installation and IT policies for German and English locations.

Please some help me in solving this issue.
Has any one encountered this type of issue.