Can't remove back cover Latitude E6400

I'm having trouble removing the back cover from a new E6400. I have removed the screw in the center of the panel. I have also removed the battery.
The cover plate is still firmly in place, and I cannot seem to free it from the base.

I know I have taken the right steps here, but does anyone have further suggestions for prying it away, or something like that?
I think it's hung up on the DVD side, because I can move it a fraction of a millimeter on the other edge.

I have already done this on 2 other identical laptops without issue.

 

Ok, I got it after about 10 minutes of struggle, I decided to remove the 2 grey plastic tabs by the HDMI and LAN ports. I then used a flat screwdriver on the exposed edge of the plate. It took a serious whack, but it came open.

Hope this hopes someone.

 

The technique of removing the screw and then putting thumbnails (or maybe a screwdriver) into the join at the back near to the battery to then slide the base forward has always worked for me.

I hope you manage to get the base back on properly. It seems to be a very tight fit.

John

 

The cover isn't the same as the one as the M4400? The one that -slides- off it's footing after removing the screw?