I recently was having issues trying to get my applicationtoproperly shut down SolidWorks in VB.net 2005.  I did astheAPI help suggested and did the following:

swApp.ExitApp()
swApp = Nothing

This doesn't quite work.  Instead I specified thefollowingand all is good.
 
swApp.ExitApp()
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(swApp)

Unfortunately there is no mention of this in the API help. Ifound this out from someone who is a much better programmerthanme.

I thought I would share this with everyone.  But thenagainmaybe I am the only one who didn't now this.  Hopefullyithelps someone.
SolidworksApi macros