resizable breaks option selected values in <select>

I found a very strange behavior of <option selecteded> within a <select>. selected options are NOT posted to the action page if resizable is applied to the <select> tag on FF 3.6.3 and O10.51. In IE 8 it still works.

Here's the code that generates the problem:

<select name="show_id" size="#min (select_height, get_shows.recordcount)#" multiple
<!--- 
   class="resizable"
--->
   style="width:95%"
   onchange="if (this.form.show_id.selectedIndex < 0) {
                this.form.price_1_text.value = 'na';
                this.form.price_1.value = 'na';
                this.form.price_2_text.value = 'na';
                this.form.price_2.value = 'na';
                this.form.price_3_text.value = 'na';
                this.form.price_3.value = 'na';
                this.form.price_4_text.value = 'na';
                this.form.price_4.value = 'na';
             } else {
                this.form.price_1_text.value = a[this.form.show_id.selectedIndex][0];
                this.form.price_1.value      = a[this.form.show_id.selectedIndex][1];
                this.form.price_2_text.value = a[this.form.show_id.selectedIndex][2];
                this.form.price_2.value      = a[this.form.show_id.selectedIndex][3];
                this.form.price_3_text.value = a[this.form.show_id.selectedIndex][4];
                this.form.price_3.value      = a[this.form.show_id.selectedIndex][5];
                this.form.price_4_text.value = a[this.form.show_id.selectedIndex][6];
                this.form.price_4.value      = a[this.form.show_id.selectedIndex][7];
             }">
   <cfloop query="get_shows">
      <option value="#HASH#" selected>#trname#, #name#</option>
   </cfloop>
</select>

This is coldfusion, so <!--- ---> are comments, #...# is evaluated at the server.

Visually, everything looks identically as before without the resizable class, but ANY selected value is no longer posted to the server if I apply the resizable class. This is strange, because resizable works fine in other places, also multiple times on one page. On the failing page it is the 2nd time resizable is used, the 1st time on a <textarea>.

Strange is that with MS IE 8 it still works correctly. I was hinted to that by a customer who works with IE wanting to switch to FF where the code no longer works.