I dont know for certain whats causing the problem, but to find out a bit more id suggest the following.
Export out of PPRO into some sort of file format, and play it back. Assuming theres no sync problem there, bring the file into your authoring program.
Play the file in the authoring program, if theres no sync problem then continue.
That would at least help you figure out if premiere is doing it, or your authoring tool.
As far as your colourgrading, no there is no easier way than hooking up a monitor to your edit system to check the pictures during the edit.
~Peter Berthet
Sydney, Australia