Standalone recorded video won't seek

[kurbads]

Sorry for long post.
I was asked to add menus and create labels for bunch of DVDs recorded on standalone DVD recorder from various sources - digital camera, VCR, satelite and air broadcasts.
All disks contain three title sets, but each title set is 3-5 GB large. Windows explorer shows the total size of data on DVD5 like 9 to 15 GB. The contents of any title set still remains the same. The file alocation table in al cases points to same data.
DVD has chapters every 5 minutes. And skiping them is only way to navigate the disk. If video is simply added to project in DVD Author (through Add DVD video button) - it gets out of memory when outputing to folder (even if memory is 2GB RAM).
The timecode of video every minute restarts from 00.
TMPEGEnc DVD Author when draged to the middle of video shows different picture in timeline from preview and also gets out of sync. While when not draged but watched from start everything displays and sounds right. The video also can not be seeked in MPlayer Classic.
I extracted video with DGIndex because DVD Decrypter was going to extract all 9-15 GB. Each disk contains 1 to 5 PGCs. I found each PGC in DGIndex dragging the slider and extracted each seperately because DVD Decrypter and VobEdit did it wrong. Yes, I did not try PGC demux.
Since the video does not seek well on PC, I am afraid it won't seek properly on DVD.
I understand the timecode problem is still present in demuxed video?
Can I fix that without reencoding the video? The quality of video at low bitrate (4 hours per disk) is quite good. I am afraid I will not preserve it even using CCE. Also it is like 20 hours of video...

[Alex_ander]

Did you try fast time code fixing in VideoReDo?

[kurbads]

To use the files in VideoReDo, I had to multiplex them with TmpegEnc tools. They are "Rewriting header..." during operation. Looks, like it fixes everithing.