Scroll bars appearing on some blocks after upgrade to 3.8.3.1

Hi, I am having the same issue as this person in the AdRotate support forums where scroll bars appear in blocks after upgrading to 3.8.3.1.

http://www.adrotateplugin.com/support/forums/topic/scroll-bars-appear-on-ad-3-8-3-1/

However, my blocks are configured correctly. My ads are 300×250 and 300×100 and blocks are configured with the same size. I set both blocks to have 0px margin, padding, and borders.

I downgraded to 3.8.3 first to fix the issue.

http://wordpress.org/extend/plugins/adrotate/