I have been getting a strange error message from my Tcl Tk application

    grab failed: another application has grab

I am not sure why I would get this error, however I think it is caused 
by my attempt to return the focus to each dialog box I call so that the 
user cannot place the dialog into the background.

Is it possible that by doing a focus that the grab command is called.

If not can anyone help me understand why this would come up once in a while.


Michael