[boro boy]

tried as you said and the cdart just went back to been blank again, but if went through context menu, music artwork, refresh item and then restart kodi the cdart then stick again, though for some reason this does not work for some artist's such as A-ha, Ac-Dc, Adele, Anouk etc... I have also noticed when doing it this way to get the cdart, if an artist album has more than 1 CD it will not bring up the cdart either.

OK, we're getting there slowly...

I forgot to mention that after clearing the cache you had to restart Kodi.
Now we have to find out why it isn't working for some artists. A few more questions:

1. For the artist's that are not working, can you confim that you indeed have cdart for those albums ? Not albums have cdart available.
2. Can you check if the folder on disk has the same name as the artist's name in Kodi ?
3. For Multi disc albums, do you have your songs in a subfolder with the discname ?

BTW: If you're Dutch and prefer to continue in Dutch you may also send me a PM.

Slowly but surely lol, No I am not dutch, I am from the mighty shores of England so that stops that!! lol

Right here goes:

1) - yep cdart is present in all the albums I have.
2) - yes just checked and the folder name is the same as appears within kodi
3) - right for an example of how the folder structure is for a multi disc album it is as follows: Music/A/Adele/19/CD 1 & CD 2/

Also here is a copy of the kodi log file incase that helps you out - http://pastebin.com/pqteRUhi