Elite 7 DSI refresh rate

I finally got out on the water to try out my new Elite 7. I noticed when I zoom in on the chart map or if I am running at more than 10 MPH the refresh rate on the screen seems slow to me. When the cursor for the boat approaches the end of the display, the screen goes completely white for a few seconds before refreshing with the new view. Same thing if I hit the zoom on the chart page. It goes completly white and after a few seconds it comes on with the new view.
Is this typical for Lowrance units? I have always had HBs and the refresh on it is instant. I have never had the screen go blank before it refreshed.
Like the unit, still learning all the bells and whistles.
Thanks,
SeaRay
PS
I forgot to add that I am running a Navionics Premium card and I have the latest updates on it.

At what zoom level do you start seeing this?

Jason,
It does it each time I change the zoom level and when I am running at speed it will go blank and then refresh as the curser nears the edge of the display. You have to zoom in to a certain level before the contour lines show up. I am usually at that level and on down to the 50 ft scale if that makes sense. This is a new unit to me so I am still learning, however, my buddy has a Lowrance (HDS 7 I think) and it does not do this. His boat runs over 40MPH and he does not loose the screen as it refreshes.

I have had this compliant several times on this unit. The processor on this unit is not one of the fastest and the more detailed the map it seems the worse the refresh rate is. I talked to Lowrance about this and they said generally you are zoomed in too far when this happens and you need to zoom out until it can keep up. Not sure how far out that would be, maybe you can give me some insight to the range.