You didn't happen to recently go from a two monitor setup to a single screen, did you? It sounds like some other problems that have been posted here, only that the entire Monarch window disappeared for those users.
If that's not it, then you're probably best off calling tech support for quick help.
Try moving the filter dialog blindly. Click the Filters icon in the toolbar, the hit Alt-spacebar then M and hold down the arrows keys to drag the dialog around your screen.
Worth trying. :confused:
I had the same issue, where clicking on the filter icon would essentially freeze Monarch, and every other keystroke would simply elicit a bell tone. Only Esc would return control back to the main window. The only hint was a shadow at the top of the screen (win 7), but you could not grab the window to return it to the desktop. My guess is that the issue was caused by the monitor switching that occurs when I telecommute, going from two monitors at work to one at home (when I'm telecommuting).
I totally appreciate Data Kruncher's information (it worked), as I was in a critical timecrunch, having to run 2gb+ data through a monarch model and was using the filters to test conditions.