To be a bit more specific, hold the BB button down momentarily until the screen goes black with a bunch of icons on it. That's your list of running apps. At least 5 will always be there - the browser, the home screen (the house icon), the Phone app (to receive calls, of course), BlackBerry Messanger, and the Messages app (to receive pushed email and other notifications). Those apps alone shouldn't be causing any problems for you. Although, the browser could he a problem if you switched out of it while a busy page was still running. But you have to task-switch out of the browser to do that. If you back out normally, or hold the back button down to close out, that should close any page you're in.
Originally Posted by frisco49ers
Beyond that, it's any other apps that may be running that we are interested in knowing about.