Topic: [jquery] drag'n'drop + slider -> $.widget is not a function

Hi,
I'm really getting crazy with jquery, I included those:

    <script src="jquery.js" type="text/javascript" charset="utf-8"></script>
    <script src="jquery.dimensions.js" type="text/javascript" charset="utf-8"></script>
    <script src="ui.mouse.js" type="text/javascript" charset="utf-8"></script>
    <script src="ui.slider.js" type="text/javascript" charset="utf-8"></script>
    <script src="ui.core.js"></script>
    <script src="ui.draggable.js"></script>
    <script src="ui.droppable.js"></script>

and I'm getting this error
$.widget is not a function
[Break on this error] _refreshValue: function(animate) {
ui.slider.js (riga 499)
$.widget is not a function
[Break on this error] _uiHash: function(event) {
ui.draggable.js (riga 391)
$.widget is not a function
[Break on this error] ui: function(c) {

how is it possibile if I have deleted all my javascript scripts from the current page?
I noticed the if I also delete
    <script src="ui.mouse.js" type="text/javascript" charset="utf-8"></script>
    <script src="ui.slider.js" type="text/javascript" charset="utf-8"></script>

I'dont get any errors, but I can't run my script because I have a slider in.
Any hint?
thank you