jQuery Spy vertical ticker after 4th iteration list items are animated down increasing the height of container

Question

we are using jQuery spy plugin by Remy Sharp, to build a vertical spy ticker. The module works fine for first 4 iterations and thereafter behaving strange - the list elements are eventually crawling down (increasing the actual height) of the parent container (a yellow border seen on the bottom is the actual border of parent div).

We don't see this problem on the original demo provided with this plugin website (http://jqueryfordesigners.com/demo/simple-spy.html).

But it happens only on our page, something tricky is there that needs a fix .

Thanks a lot for your support, in advance!

PS. for your reference on the spy plugin source: http://jqueryfordesigners.com/simple-jquery-spy-effect/