Last time I also having this problem. It happens when I upgraded the phone version (previous version) where I took out the memory card (2Gb) and replace with the one that I got when I bought the phone (128Mb). I did this because I afraid I will lost all the information/files that I stored in that memory card (2Gb). Before that, I do some back up as proposed by the updating software. When I finished updating the phone version, I switched back the memory card (from 128Mb to 2Gb) and the problem (keep installing softwares that are stored in memory card) starts happen.

Last two weeks, I updated the phone version again to latest one (210.21.006). This time after do the back up using Nokia PC Suite, I kept the memory card (2Gb) in the phone and start updating until completed (after several times tried). After completed, my phone is like new. Factory setting. Then I restored the data using Nokia PC suite. All the setting back to previous one (before updating) and I got no more problem of keep installing if I switch off/on the phone.

For you guys who are having this problem, try to back up your data using Nokia PC Suite then restore back. If you success.. then good for you but if it is fail.. nice trying. I just give some idea on how to solve this problem.

Bye.