Win Form app controls turn Black and app locks up when minimized too long

I have a Windows Form desktop CRUD application. The users are finding that if it sits too long minimized all the Controls turn 开发者_JS百科to Black Filled Boxes and it becomes unresponsive.

This is my first large app and I am having trouble even figuring out WHERE to start on this. Searching the Web for 'Black Filled Boxes' hasn't been real productive...

What am I doing wrong? Where can I start looking? My app is a single Form that embeds the neccessary UserControl in the Main Area based on what they select in the Navigation menu on the Form.

Example; They select Insurance and it displays ucInsurance in ShellForm's main content area.

Idea's? I'd appreciate anything. I tried turning Double Buffer on for the Shell Form and all User Controls but that hasn't seemed affective.

Start by looking how your form is behaving with Taskmgr.exe. Click Processes tab, View + Select columns and tick Handles, USER objects, GDI objects. If any of these columns for your process keeps climbing up and up you've got a resource leak, usually by forgetting Dispose(). GDI being the likely one from your description. The show is over when it reaches 10,000.