Nokia E-series memory card password?

I recently upgraded my Nokia E-XX Software revision, and was told two times to check for a memory card password.
I clearly remember I didn’t set any, so I just went on with the upgrade.
Everything went fine until the phone rebooted and asked me for the memory card password. I didn’t set any, so I obiouvsly didn’t know any either.
Trying to read the memory card from an external reader turned out to be useless, as the card seems encrypted.
I was formatting it when I decided to to a brief search and found this article: Another Tip for Password-protected Memory Card by Antony Pranata.

Well it seems I actually set a password on the memory card, just a st I didn’t know. The memory card password is the remote lock password. Not very clear on the Nokia side:  although I like to discover the memory card isn’t a plain filesystem, at the same time I’d like to know and be clearly informed about what I’m locking out when I set some passoword.