Inserting custom <ul> and <li> tags for left column widget only

Hi guys! I have found your theme recently and I am really amazed of the power of all the settings. However I am sure it is not something new for you, so I will go directly to the point.

My problem is that I am trying to insert an Accordeon Menu using jquery on Wordpress 2.9.1 and Atahualpa 3.4.51. My website is http://gnm-bg.com. As you can see, the menu is inserted smoothly using the simple text widget and adding my own code. However I have a problem with the definitions of the <ul> and <li> tags in the style as the officially defined ones are applied but not my personaly added. I have read about the recent changes for the styles in the widget (div.widget ul, div.textwidget) and I am sure that there is something I am missing here, so any help will be really appreciated.

I have had a solution to my problem by setting Widget list items in the different levels to have margin, width and padding = 0, however in this case the right block is not appearing as before (the grey rectangular is gone).

So my question is how can I insert an html in the widget and if I need to use different styles for my <ul> and <li> how to define them without interfeering with the other blocks/widgets?

To see my problem you better click on one of the expandible menus. It is written in red color. My problem is the same gray rectangular and the space after it.

Thank you in advance for your amazing work. As soon as I have my funds organized I will pay back all the help.