Ending Fade Timing Between Regions

I have a layout with two regions - left and right. Running 1.7.9

In the left one I have an image with a 30 second time and 1500ms fadein and fade out.
In the right one I have two html elements each of 30 seconds in length and 1500ms fade in and fade out.

When played, the left and right fade in together and the right fades in and out as it should. The problem is that the right one finishes about 3-4 seconds before the left one fades out. I have adjusted the timing to no avail and I guess I need a little help here to make them both fade out together.

The HTML elements will have a variable loading time, and the fades won’t start until that loading has finished, so I don’t think it’ll be possible to exactly syncronise these as you want.

I understand but what is odd is that the side with the html fades out first and then the side with only an image fades out at layout end. One would think that this loading time would make the html side late.