Hi Andrei,
as I told you soon after OCD 6.1.7 was released, the multivolume bug for tracks' Musicians/Credits (see topic 'OCD Musicians/Credits Tracks BUG with BoxSet') was totally resolved.
But I found the last main obstacle to my theme, it's another multivolume bug, but slightly different:
if I have a 2CD with two different bands per cd, or the same band but different guest per cd, my theme splits in two sections the layout for musicians/line-up, guest and so on.
This time OCD instead of displaying only the datas of the first volume, merges all datas for each volume.

For example if a have a double cd like this

CD1
BAND:
Roger Waters(Bass, Vocals)
David Gilmour(Guitars, Vocals)
Nick Mason(Drums and Percussion)
Richard Wright(Keyboards)

CD2
BAND:
Roger Waters(Bass, Vocals)
David Gilmour(Guitars, Vocals)
Nick Mason(Drums and Percussion)
Richard Wright(Keyboards)

GUEST MUSICIANS:
Dick Parry(Saxophone)
Nawasa Crowder(Backing Vocals)
Mary Ann Lindsey(Backing Vocals)
Phyllis Lindsey(Backing Vocals)

Orange CD shows this layout

Disc 1
Roger Waters(Bass, Vocals)
David Gilmour(Guitars, Vocals)
Nick Mason(Drums and Percussion)
Richard Wright(Keyboards)
Dick Parry(Saxophone) - Disc 2
Nawasa Crowder(Backing Vocals) - Disc 2
Mary Ann Lindsey(Backing Vocals) - Disc 2
Phyllis Lindsey(Backing Vocals) - Disc 2

Disc 2
Roger Waters(Bass, Vocals)
David Gilmour(Guitars, Vocals)
Nick Mason(Drums and Percussion)
Richard Wright(Keyboards)
Dick Parry(Saxophone) - Disc 2
Nawasa Crowder(Backing Vocals) - Disc 2
Mary Ann Lindsey(Backing Vocals) - Disc 2
Phyllis Lindsey(Backing Vocals) - Disc 2

Obviusly the same thing happens if musicians differ per cd (f.i. CD1 Pink Floyd / CD2 Genesis)

I pasted a simple example code to test it...

<dax:volume>
<b><dax:volumename/></b><br>

<u>BAND:</u><br>
<dax:member>
<dax:membername/><dax:if(memberrole)>(<dax:memberrole/>)</dax:if><dax:if(membertracks)> - <dax:membertracks/></dax:if><br>
</dax:member>

<u>GUEST MUSICIANS:</u><br>
<dax:guest>
<dax:guestname/><dax:if(guestrole)>(<dax:guestrole/>)</dax:if><dax:if(guesttracks)> - <dax:guesttracks/></dax:if><br>
</dax:guest>
<br>
</dax:volume>

It should be the last big thing I found that doesn't work for my theme, there are other few things and some request, but I'll post them in another topic; this is the most important thing for me, hoping you'll fix it.

Thanks
Emanuele