When you open a web page in Firefox for Android, the browser may move the cursor to the first form element on the page, whether it's a search box, login box, etc., and that can cause the keyboard to display. I'm not sure if there is a workaround for that. But on the home screen of your device, I have no idea. You could try an Android enthusiast forum like the following: http://forums.androidcentral.com/samsung-android-tablets/