Hello, at first, many thanks for the great paint.net software.
Since Version 4.xx, the paint.net doesn't remember the actual window size by closing the software over the "X" on the right top, or try to close over the menu. In the older versions of paint.net it works fine.
Please, Rick, insert this feature again in your software. It is annoying, at each start of paint.net, to set first the window size for the own work.