1Ds Mark III white edge on the top side (landscape shot)

HI, I've owned a 1Ds Mark III for a couple of years, just today, that I found out this camera gives a white (lighten) edge on the top side (landscape), or on the left side (portrait).

It is noticeable when the shutter speed is 1/500th and more obvious over 1/1000th of a second.

Any ideas folks?

Thanks!

looks like the shutter is sticking or failing.....

Valucolso wrote in post #14498542
looks like the shutter is sticking or failing.....

Thanks, will explore on that.

Valucolso wrote in post #14498542
looks like the shutter is sticking or failing.....

+1.

Replaced shutters, problem solved, thanks you guys.