Width problems since 6.x-2.5

I have a jCarousel block view inside a div of 622 pixels for the width. The view uses "None" for Skin and "Auto" for Number of visible items.

Until 6.x-2.4 included, the carousel was perfectly fitting in the 622 pixels width. But with 6.x-2.5/2.6 the width is very larger. How could I limit it again to 622 pixels ?

Thanks for your support !