Solved! Go to Solution.
1. Un-install anything that is not really necessary.
2. If any applications are installed in the phone memory un-install and re-install on the Memory card..(..note that some applications need to be installed only in Phone memory).
3. Clear the browser cache.( within the Browser-->Options-->Privacy...). Make it a habit of doing this after every use..
4. Keep minimum of messages on the phone.. If you need to keep them, Sync / Back-up with Nokia Suite on PC.
Though a time consuming job, if you want to start afresh do a Soft Reset by dialing *#7370# followed by 12345 (Default code unless set by you) when prompted. Be warned that this will erase all data from the phone memory..so back-up before doing it. You will need to restore data and re-install a few applications (even if they are on the Memory Card)..but the results will be surely rewarding.