On the jsfiddle link provided below, I have a paragraph with text, and then an input box. I use jQuery UI to shake the input box, but bizarrely the shake effect starts one line below the text.
if you check source code during the effect, you see that the input is wrapped by <div class="ui-effects-wrapper">
and this is why it folds to next line. I am not familiar with mootools, but quick'n'dirty fix would be to assign display:inline
to that div:
<style type="text/css">
.ui-effects-wrapper {
display:inline;
}
</style>