As much as this is annoying I don't know how you captured the footage into the computer? tape based via WMM or PPro?...HDD based copied to HDD then edit?...
Anyway, you have it in the computer now. If the footage interpreted works properly as a whole clip in the source monitor without any sync issues. I'd do an export to DV AVI from there. I know its a copy and you should save it to another folder (called reExportDV - or something like that... try to keep the same file names). Use the 48K DV settings in Export>Movie... adjust the settings to be correct for the project settings (so they are then native to each other). Once you've done this to all the clips from the source monitor, without any in/out points - try to unlink all the media in the project panel. Then Link them to the new folder with DV exports. if the names are the same hopefully they will all relink to the new clips, and maintain all the editing you've done too. Because the clips settings will now be native to the 48K timeline the sync problem should be gone.
- Jon Barrie :)
How many editors does it take to change a light bulb?
www.jonbarrie.net