Custom Sidebar keeps changing to Default sidebar when using Tags or Categories

I have a test website I created with Artisteer 2.4.0.26802
I’m using WordPress 3.5.1

My client now wants 2 sections within it – each with their own dedicated sidebar with Menu, Categories and Tags.

I’ve set it up using the following plugins: AVH Extended Categories, Ultimate Tag Cloud and Custom Sidebars

Using these (plus WordPress’s Custom Menu widget) I’ve been able to achieve what the client wants.

The only downside is that when someone selects a Category or Tag in the Menu, the correct information appears on the right BUT the menu on the left changes to the default Sidebar. Fortunately, since I keep the default Sidebar empty, its not too distracting – but it does mean people have to click on a page to bring the correct sidebar back

NB. The Custom Menu widget doesn’t cause this problem

Is the problem caused by the Artisteer theme or have other people encountered this with other themes?
Or is this an Ultimate Tag Cloud Problem?
Or AVH Extended Categories?
Or Custom Sidebars

Here is the link:
http://test1.nickwingfielddesign.co.uk
The test tabs are Experts and Good Practice

http://wordpress.org/extend/plugins/ultimate-tag-cloud-widget/