Some applications require more capabilities than what can be granted with a self-signed certificate. Unless they're officially Symbian Signed, they can be signed through Open Signed Online at Symbian Signed, by following these steps:
- Download the package to be signed.
- Go to Symbian Signed website and choose Open Signed Online on the front page (or try this direct link)
- Enter the IMEI number of your phone (you can find this by typing *#06# on the phone), your email address, and point to the install package you just downloaded.
- Select the capabilities needed for the specific application. If unsure, select all (there's no harm in doing that).
- Fill out the captcha, review the legal agreement, check the box if you accept it, and press send.
- Wait for a confirmation mail sent to the email address entered earlier.
- Visit the URL in the mail to confirm that the package should be signed.
- Wait for another mail telling you that the signing is complete. Visit that URL, and you'll get the signed package which you can install on your phone.