Widget images jumping

I have just added a linked image widget to my sidebar, but when I mouse over the linked image on the live site, the image/link jumps down from under the cursor. How can I change this, so the image/link remains stationary upon mouse over? I read the forum and tried the advice recommended here http://ww.wp.xz.cn/support/topic/mouse-over-issue?replies=4, but it had no effect.

My site is here: http://www.pgringette.ca/

Thanks!