Atapi DVD burner problem

[confus-ed]

Welcome to wd forums sedrickf .. 'Invalid function' is a common error & can mean a number of things, however the most likely one, is 'class filter' issues...

CD\DVD drives don't 'really' have drivers in the way that other devices do, they use standard ones provided by windoze & then s/w vendors add functionality (such as burning functions) by adding a 'class filter driver', these get 'mussed up' by other drivers getting introduced due to a lovely programming concept called 'undefined forwards', where ecah 'driver' is required to interact with all the others without 'really knowing' what they might be .. this problem is tremendously common & the answer is generally to delete all the errant class filter drivers by deleting a registry key & then reinstalling whatever is your prefered burning software ..
(as this is a common issue its already covered in this forums sticky, which has details of what registry key to delete )

EDit: I think I was busy answering another question reading that back ! .. but class filter issues can cause 'invalid function' most definately .. however since this question is concerning 'preburnt' cd's - can I ask - do you know what 'finalised' disks are ? If you do , are all/any of the disks finalised or do they have open sessions on them ? ..