I also noticed that in your formmain's unload event your calling itself to unload again in that procedure creating a circular reference.
VB Code:
  1. Private Sub Form_Unload(Cancel As Integer)

  2. Unload FormSplash

  3. 'Unload FormMain 'Circular ref.

  4. Set FormSplash = Nothing

  5. Set FormMain = Nothing

  6.  
  7. End Sub
Also, switch the event to the Form_QueryUnload event instead. In case your clicking the 'x' at the top right corner to close the app. it will be sure to close and destroy all objects.