WP Carousel 1.1 should use jCarousel by default. If it is not using it like in your case, I think the easiest way to solve the problem is:
0) Make a backup of WP Carousel's folder
1) Download WP Carousel 1.0 and replace version 1.1 with version 1.0
2) Toggle to jCarousel all the carousels
3) Reupload your backup
I want to release a new version of WP Carousel with that kind of bugs fixed, but I'm very busy this year, and I think this new version won't be released until July-September. I know it's a lot of time, but I'm really busy and I can't work on WP Carousel right now.