Vista - Windows DVD Maker - 99% Burn Error

Hi

I have been trying to burn wmv files onto DVD thru windows dvd maker. Some background

i. This used to work
ii. There are four files in the project
iii. I have not put them into windows movie maker prior to addind them into dvd maker
iv. I have over 200gb of free disc space
v. combined length of wmv files is about 70% of the disc memory I am trying to burn onto
vi. I have tried changing burn speed (medium and slow) to no avail
vii. Burn process starts, gets to around 1.0%, then within a few seconds jumps to 99% and ejects the disc
viii. No detailed error message is given, simply, error burning to disc.

Please help, I have looked thru numerous forums but nothing suggested in them has made an iota of difference

Is there really no-one here that has an answer?