It's a known problem from Artisteer with auto-detect width menu.

By a search on this forum, you will find different topics dealing with this problem.
Today, i don't know a good reason to prevent this.

This is a problem from your template and a script calling the wrong class on iCagenda page (for a reason i don't know today...)

You can edit your template.css file, on line 598, OR maybe try by adding this in the component css file, in theme pack of iCagenda :

ul.art-hmenu ul.art-hmenu-right-to-left {
right: auto;
left: 0;
margin: -10px 0 0 -30px;
}


And after this change, it must work in every case, and always align on left (display on right), and not auto align on the right.

But if you want a good menu for your site, you can install and use MaximenuCK !