Program fails to shutdown or close

I always have 2 servers open, when I click either file/exit or red X the program doesn't always close without clicking red X again.
Sometimes it fades in color and says "not responding"
 
this is an intermitent problem, it doesn't always do this.

1. Install the latest version of SmartFTP
2. Please provide instructions on how to reproduce it.
3. Version info from the menu: Help: About - System Information dialog
4. Hang dump: Paragraph "If SmartFTP hangs" at https://www.smartftp.com/support/kb/how ... f2594.html