I am recieving the following exception when attempting to save changes to the RDP settings for any connection.

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.ArgumentOutOfRangeException: Index was out of range.  Must be non-negative and less than the size of the collection.
Parameter name: index
   at System.Collections.ArrayList.get_Item(Int32 index)
   at SmartCodeVnc.RDPClientForm.OnClosing(CancelEventArgs e)
   at System.Windows.Forms.Form.CheckCloseDialog()

************** Loaded Assemblies **************
<skipped>

Could you please answer on a couple questions?

Was RDP dialog working for your a previous builds, or the .70 build was the first one your ever installed on the computer?
Can you please compare the list of screen resolutions available in native RDP properties dialog and Display properties of your display. Are they the same?
Does crash still ocurres If you choose some other resolution in properties dialog?