A demonstration of the issue is in this stackoverflow item
I've had success with knockout 2.1.0 in many similar cases.
To reproduce, use this jsfiddle:
simply change the knockoutjs version from 2.2.0 to 2.1.0
Yes, there was a change in Knockout 2.2 regarding the foreach binding. In 2.1, the foreach binding was sometimes erroneously exposing it's dependency to sibling bindings, and this was fixed in 2.2.
So the real bug is in the jqAccordion binding because it doesn't have any dependency that will cause it to update. I was able to make it work by adding an option to jqAccordion to give it the correct dependency: http://jsfiddle.net/mbest/NE6dm/1/
BTW, this shows how it also doesn't work in 2.1.0 when the foreach binding is specified differently: http://jsfiddle.net/mbest/NE6dm/2/