Page 1 of what doe`s this message mean

Please could some one explain this message i keep on getting, when burning
DVD Files, I`m using Nero 6, and DVD Shrink 3. 2, (could not perform Disc-at-once).
then ejects the disc, this problem only seem`s to occur when Dvd Disc R+, i have tryed
TDK and Benq disc, if i try DVD RW and it seem to write these okay, Nero loads the DVD`s
Files okay, the writer is VOM-12E 48X, which is suppose to write in DVD+R DVD-R and -RW +RW, another message that come`s occasionaly (POWER CALIBRATION ERROR).
thank you for any help

Out of curiosity are you trying to copy discs on the fly? or is nero maybe set for doing this i.e copying straight from 1 disc to another. Thats the only thing i can think of. cannot do disc-at-once would suggest that it cant write burn straight off as the source disc is in the drive.

If your burning discs from your HDD then i havent got a clue, lol

Bryan