subtitle getting out of sync, alltough they were good before their added.

[fibola]

hi,
im tring to add subtitle to a dvd movie with dvd lab pro as i always do but this time i getting a sync problem with the subtitle im adding after the project comeplete.

the out of sync is changing along the movie , at the begining everything ok and during the movie its getting out of sync .

usually when im having that kind of problem im using subtitle workshop to fix it but in this preticular movie at subtitle workshop the sync is good all the movie .

anyone know what can i do to solve it ?

thanx