Expired Certificate Error Solution For Nokia 5800 and s60v5

I used Nokia PC Suite to backup all these four components instead of using Nokia 5800 inbuilt backup function, which doesn’t has an option to backup Notes (but I’m not sure the ALL settings will back up the Notes).
Remove the microSD memory card.
When the phone is powered on, don’t simply remove the memory card. Otherwise, the memory card content will likely corrupt.
For past few days, I’d been busy finding workable solution to the annoyed “expired certificate” problem that happen when I attempt to install SIS/SISX program files in Nokia 5800.
There are forums and blogs mentioned that the version 10 firmware is well known for this “expired certificate” bug and thus should upgrade to the latest firmware version 11.0.008.
However, my Nokia 5800 firmware is already at this latest version out of the box. So, what’s next?
i had purchased my new nokia 5800 set.and i was really disappointed when i saw all this crap.i was like what the heck man.what is the use of this set when i cant even update or install anything.i was really disappointed but then i got something interesting to fix this crap and here it is to share with you
But now, I’m pleased to tell you that I’ve fixed this “silly bug” at last try,
How to solve the Nokia 5800 “Expired Certificate” error that fails most SIS program files installation?
To be frank, I just don’t believe that one-line reply could be a real solution for me. But, I’ve ran out of ideas and found nothing newer than his suggestion.
So, I simply take it as last resource to try. Eventually, this simple trick does works magically, and I can’t wait to tell him how excited and grateful I am!
For reference, here is the solution in detail
(in case you’re not sure what additional steps I’d done on top of his one-line guide):
Backup all messages, notes, calendar entries, and contacts.
To remove the microSD card when the Nokia 5800 is switched on, press the power key (the button next to the power charging port), scroll down to locate and select Remove Memory Card, opt “Yes” as the “Removing memory card will close all open applications. Remove anyway?” message is displayed.
Shortly after, the “Remove Memory Card and press OK” message appears, and then the microSD is ready to be unplugged or removed from the dedicated slot.
Notes, both SIM card and microSD card slot are next to each other on the same side (another defect, personally), don’t be careless and end up corrupting the SIM card (if you happen remove SIM card instead of microSD card).
Format the Nokia 5800
Access to touch keypad and enter *#7370# secret code (not so secret, anyway) to restore phone settings to factory default (even the user data and files are deleted).
Next, you’re prompted to enter the Nokia phone lock code. The default is 12345, if this code hasn’t been changed by yourself or any one.

Then, the phone restarts and you’ve to select the country region (just select your own country from the list, in this case), followed by request to enter current date and time.
When the phone is ready, power it off again to re-insert the memory card (for highly safety measure, unless there are nothing important kept in the memory card, e.g. picture, music, documents, etc).
As the phone is switched on again with memory card inserted, the “preparing memory card” message appears.
Finally, I’m happy to be able install all my wanted Nokia 5800 programs and games without getting the “Expired Certificate” error message that says “Certificate may not yet be valid, is expired or phone’s date setting may be incorrect”