Does this happen when you are developing an AIR application?
Not sure , I am only a basic user. It happens whenever I am trying to use reader.
In that case, you might try this forum: http://forums.adobe.com/community/acrobat/acrobat_windows This one covers a different Adobe product.
What it sounds like is that one of the helper programs that reader uses, called plug-ins, isn't working. If you've recently added a plug-in, you might try removing it. Otherwise, I would be inclined to uninstall reader and reinstall the latest version.