I too get the same error in Nero "dvd files reallocation failed....."
after reading some posts, I tried the following (and it worked):

- I deleted or otherwise removed ALL files from VIDEO_TS folder
except the actual movie files (*.VOB)

- I downloaded, unzipped and ran IFOEDIT, then clicked on
"Create IFO" button, and pointed to the first VTS_01_1.VOB file.

- after a few minutes IFOEDIT examined the whole folder and created
4 new files (two IFOs and two BUPs)

After this Nero burned this DVD without an error.

hope this helps someone