I am playing FLV's that are 320 x 240 (no skin). I have a graphic symbol that is in the same location as the FLV. When the FLV isn't playing, the graphic is visible.
Now, the symbol is also 320 x 240. However, when I play the FLV's that sit on top of the symbol, the graphic symbol is visible for 10 pixels to the right of the FLV's, as if it is actally 330 pixels wide. Now, I can fix this by shrinking the graphic symbol to 310px wide, which effectively hides it totally under the playing FLV's, but the graphic is the same as the last frame of the FLV's, so when I play another FLV, there is the appearance of a sudden jump in width.
I hate to say this, but are you sure the FLV component is actually 320x240? Even if you set the parameter to 100% of source, it's still better to be sure the component on the stage itself is actually sized.
Also, check the coordinates again.
I sometimes get a similar problem but realize that I've just not sized the component independantly.