I do not like it, that now the genres are automatically locked, when I edit it. It should be possible to disable this, like it is possible with the automatic locks for disc ID and SRP.

I have no problem updating and adding extra genres and I could submit them too,.. 
Where are they locked?
Is there something I'm missing here??

The locking of certain fields when those firelds are initially submitting/contributing with a new profile is to preventing
1) from changing the original SRP, with out documentation. (some people have and still submited the price paid instead of the SRP. And there have been a ping-pong if the SRP differ by a few cents.
2) Disc ID, I can only presume that goes to defining the profile with the UPC , especially if there isn't one.
3) Genre, presumably to cut down on the ping-ponging.

You can change any field or area in a profile in your own DB.

I keep all my profiles in the OWNED and ORDERED list locked  and I have changed them, but I don't submit those changes unless I have documentation that they where wrong..

Rhe SRPs of a number of DVDs have changed over the years, but my understanding is we are to maintain ther original SRP.