i also use sound recorder in my Nokia 6630 mobile. The name of the software is Smart Recorder. May be you can try the software.

I have two phones, one is Corby 3650, the other is Nokia N96. What I want to do is hide the audio recorder in the phone so that once I start the recording and someone picks up my phone and unlocks it and starts fiddling with it, the recorder continues recording. Right now, both phones have the recorder directly on the screen so that you have to close the recorder in order to use the phone. I want it to record silently.