Initialize now doesn't delete old database

[Psirus]

Hi,
I'm using Rockbox 3.5.1 on an Ipod 5G 30GB and have been doing so for quite a while.
Recently I decided to put a bit more order in my collection, so I updated all the tags and so on.
I deleted all the files from the Ipod, and put the updated files on.
Since it was kind of work in progress and I wanted to cross check whether Album art and tags like Album Artist worked, I put a few albums on and then build the database.
Now I have put the rest of the files on, and chose Initialize now, and all the tracks that I put on before show up twice in the database, even though they are only once on the HDD.
If I Initialize again, all the tracks will appear twice, and so on...
mfg
Psirus