Is there some quest reqirement that has to be fullfilled before the book places? I have found it in one or two of my other character plays, but with my current character no dice. Palla volume 2 is present, but NOTHING on Lamae Bal. Can anyone help me circle this vexing square?

The wiki says the book is part of the Vile Lair DLC, so I'm surprised that your found it there, but anyway it's not unusual for a book to be randomly selected from a leveled list, so there may be a substitute, or no book at all, in any particular play-through.

It is in Vile Lair DLC also, which I don't have (and that pisses me off too. ALL of the DLC should have been included in the game of the year, NON and SI expansion pack), but it is also supposed to be in Atatar Loria, and I have found it there in the past in other playthroughs. This is really f**** up. I want that book.

Wait, you don't have the Vile Lair, but you've seen the Lamae Bal book? The Vile Lair DLC adds that book to the game. Are you sure you're talking about the same book? Opusculus Lamae Bal ta Mezzamortie?

Atatar Loria has a lot of books, but it does not have that one.

In other plays I have gotten a book about the "wife" of Molag Bal and the origin of vampires etc. Is this a different text? If so, what is it, because I don't have it in this play through but I have had it in others.

I don't remember anything about Molag Bal having a wife (unless you count Vivec!) but Lamae Beolfag was certainly the origin of vampires, and I don't think she was ever mentioned in any other text in the whole series.

Where did you get the information about Lamae Bel, and what quest is it for? The books which are always found in Atatar Loria are listed here: http://www.uesp.net/wiki/Oblivion:Atatar#Zone_4:_Atatar_Loria

It isn't listed there.