The window size is something like 550 high by about 600 wide. Just enough to have a few machines (about 20) in a list.
Never bigger than half a screen wide or high. And that's on the small laptop display.
I think I know the cause -
On my own screen when I resize and close the application, then reopen, it doesn't lose it's previous size.
Problem is that this is on a lenovo x201 1280x720 screen. When I go to work I plug into a 1920x1200 display, maybe the change in resolution is causing radviewer to default?