- Go to the main menu and click on Settings
- In the Settings menu click on Phone Settings
- In the Phone settings menu click on General
- In the General menu click on Date and Time
- Click on the Date field
- Use the Right navigation key to highlight the year. To change the year back one year, press the Down navigation key once
- Click on the OK button
Now install your new theme. If you still see the Expired certificate error, change the year back another year and try installing again.
When it's installed, follow the instructions again, setting the year back to the present by highlighting the year and pressing the Up navigation key once.
Was able to finally get Skype to sign in (perhaps a coincidence?)
Turn off phone.
Remove battery, leave out for at least a minute.
Reinstall battery, reboot phone.
Wait for at least 10 minutes before running Skype.
Try running Skype (will require setting a few preferences, and then entering name/password).
Pray to the god of your choice.
Worked with N79, might also work with N78, E5 and other s60 phones?