DR 14.3: External Mattes, why offset?

Hi,
I have a clip in my timeline with an external matte in the Color tab.
But the animated matt does not start where the clip begins.
It seems to me that the matt starts from the beginning of the clip source, so I have to find the start point of the matt animation via the offset slider to match the clip start in the portion.
Do I miss something?
How canI force the external matt to play when the clip itself plays?
Jeff
I have a clip in my timeline with an external matte in the Color tab.
But the animated matt does not start where the clip begins.
It seems to me that the matt starts from the beginning of the clip source, so I have to find the start point of the matt animation via the offset slider to match the clip start in the portion.
Do I miss something?
How canI force the external matt to play when the clip itself plays?
Jeff