.IFO file doesn't have a time map, can't seek through videos

[siavash]

I received a DVD from someone in a snail mail trade and ripped it onto my HDD, but there is a problem. I can't fast-forward the show if I open the DVD by playing the .ifo file. I can go through each .VOB individually and fast-forward there, but not through the .ifo.

I also tried fixing it through IfoEdit, but I couldn't figure out how. Creating a new .IFO is out of the question since the DVD has an animated menu that shouldn't be removed.
How can I add a timemap to the IFO file?

[bullpinjohn]

Just use ifoedit, I uploaded dvd, after a couple of years someone wanted
to download it. It was missing the .ifo file. Found the prog on line. Uploaded it
worked just fine.

[siavash]

My DVD already has an .IFO file, but it doesn't have a timemap, meaning I can't fast-forward through it on my DVD player or PC. I can't make a new .IFO for it, since it currently has a menu that would be deleted if made a new .IFO.