Jeff,

By freeze the app do you mean that your menu stops working? If so the work around is to push/pop the menu like this:

push menu _msysmenu && work around for bug in VFP5 KB Article Q164868
report form (this.mcReportForm) preview &lcNowait &lcSummary
pop menu _msysmenu


>Has anyone experienced a problem with previewing a report within your VFP application? Whenever someone previews a report in my VFP app (which is quite often) they have to be careful to not use the maximize and close buttons on the report preview window title bar. When they do, it causes the entire app to freeze! If they use the report preview toolbar instead and use their mouse to resize the report preview window, this problem doesn't occur.
>
>Why should it matter if the preview window is closed with the window close button or the report preview toolbar close button? How can I avoid this error when the user closes the preview window with the window close button?