First of all, dump the memorex and never buy them again.
...perhaps memorex changed something on ther blanks? ...
Ya!, about once a week ... extreemly undependable media! Hint: if you resist this advice, you will get blasted from all six corners of heaven here on cdf. :iagree: This may be the end-all solution to your problem. Buy and burn only Verbatim +R DL media and booktype it to DVD-ROM format. Get the Verbs online if your local stores don't carry them, and just wait for their delivery. Don't buy the DL trash that is available on your local storeshelves.
If that does not solve your problem you might want to use Elby's/Slysoft's CloneCD. Be aware that CloneDVD places it's own layer break on dual layer media. It does not use the original's layer break. You might want to try CloneCD which is the more correct Elby software to use for 1:1 dual layer mirrored copies that maintain the original DVD movie's layer break point. Because it rips in "ISO Mode" rather than "File Mode". When you make use of the original layer break, you are assured that the amount of data included on both layers of the original is already correct, that being optimized by the people who mastered the DVD original.
If you wish to continue using CloneDVD, I will now subject you to my deductive pet theory. Amatuer, to be sure, but I think valid: You see, CloneDVD places an "automatic" layer break at the end of the chapter closest to the original's layer break. With certain DVD originals, they are so data packed (each layer is used to it's fullest capacity) that CloneDVD's automatic break can backfire. Sometimes ... not often. "Automatic" shifting of the layer break by even a half a chapter can mean that too there is too much data on either side of the breakpoint to fit on either layer#1 or layer#2 ... probably layer#1 since you are getting the message before burning.
But I'm not sure of this and am very willing to stand corrected if James, Olli, or other knowlegable members would care to counter my theory. The following fix worked for me, but possibly for reasons other than stated in the previous paragraph.
A simple, but possible fix would be to remove any extra titles or audio/subtitle tracks you know you don't need or, at best, can suffer without. But be sure to keep "Preserve Menus" checked. This method can free up the space needed on either of the layers for the burn to go ahead without an error message. Unfortunately, there is no way to tell, from CloneDVD's interface, which titles are on which layer so just juggle a little and see if you can go to burn.