I just took a look at this on FS2002; I did not see that line. Both upper and lower parts of the panel as illustrated in your screen shot are separate windows. Right click on the upper panel and close the window, see if the line disappears. Then re-load the aircraft, and manually resize the upper panel by moving your mouse pointer on top of it and pulling it up or down, and again see if the line disappears. I'm thinking that there might be interference between the two panel parts, but don't know why that would happen or exactly how to permanently fix, but maybe this will help someone else (or even myself) come up with an idea as to how to fix it. Also, is this happening on other aircraft?
Procedure for a cracked windscreen requires an immediate emergency dive to 10,000 feet, and divert to the nearest airport. Be ready for complaints from the passengers as some will suffer headaches, nose bleeds etc. due to the sudden pressure change..
Alan
System Specs:- Antec case, Asus M4N98TD Evo Motherboard, AMD Phenom ll 965 Black Edition CPU, 4Gig ram, Gigabyte 465 GTX Graphics.