WordPress 3.7.1 with 1.5.4 Doesn't work

Yes.
Please read this before you post: http://ww.wp.xz.cn/support/topic/need-support-read-this-before-you-post?replies=1
We can not help you trouble shoot where the problem is coming from without a link.
Did you ONLY update WordPress, or did you also update themes and other plugins?

Hello Pierre,

The problem is that your theme is force-loading an old version of jQuery. Please look at your theme’s header.php file for the following line and remove it:

<script type='text/javascript' src='http://www.marcouxmiville.com/wp-content/themes/theme1302/js/jquery-1.6.min.js?ver=1.6'></script>

If you do not fine it there, look in the functions.php file. More info here:
http://msyk.es/blog/prevent-jquery-wordpress-theme/

Let us know if you need further help. In the mean time, issue marked as resolved.