Yep. With the phone on, remove the battery cover and pull out the battery. The phone will shut off (obviously). Then put the battery back in and replace the cover. The phone will boot up.
This is normally the best way to fix any abnormalities, and works even when it seems like it shouldn't. So, to answer your question about when, pull the battery any time something strange starts to happen.
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Ian
Semper Fi 3/2/2
"Wow" is now overused. Therefore, I will use "Magic bananas" instead.
I've been using my 9700 for over two weeks [light to moderate use] and so far nothing has happened that requires or even suggests the need for a pull. I'll give it a go at the end of the month just as a precaution...
i usually pull out my battery because for some odd reason im not able to "click" on things when im using the browser... anyone know why i cant click on it? i would have to press the menu then press "open link"