Nokia E72: Memory full. Delete or move some data f...

HI All,
I've recently purchased a Nokia E72 phone for business use and after about three days of trouble-free operation it has suddenly run out of space on the phone system drive C:. This is very surprising as I am not aware of installing any apps or generating any content on C: since the last time I verified the available space exceeding 120 MB.
I keep on getting a message "Memory full. Delete or move some data from C: Phone memory.", am unable to enter the menu and the phone keeps on rebooting.
I've read a couple of posts from others experiencing this problem on various places on the Internet but no signs of a solution. Does anybody else have the same problem and/or knows the solution?
I would really appreciate any advice you could give me!

This is just my experience of "older" phones and memory issues; 
If Opera (mini) is installed, uninstall it.
Restart the phone...reinstall this "critical" application on C.
Nokia 808 again (delight Belle), Nokia E7 and X7 ( again, all on Delight Belle...after some time on Nokia Lumia 925 (retired), 1020 (not that great)and Lumia 820 (Replaced my router at home, great for internet sharing).., N9 The best device ever (use it as much as Lumia 1020), Nokia 700 (Sport Phone/My Love :-) ) Nokia 701, Nokia E6 (Should have a follow-up from Nokia among with larger screen, NFC, Autofocus), Lumia 800 (Retired After 6 weeks), -Sports Tracker-Nokia Internet Radio-Handy Safe-Skype-Bambuser-Screenshot app pro-fMobi-ComingNext-Manual TaskSwitcher-jagiTimer-Easy StopWatch-Boldbeast-Equalizer-Financial Calculator-WiMP Music-YTasks-Davi-Thumbnail Folders-BizCalendar-Tiny7-Situations-nn reeder-Sport Timer-CameraLover-CameraPro-GrabRadio-LiveScore-Poddi-Gravity-SkyFilesPro