>We've seen something kind of similar to this, where a listbox is inaccessable on a page when the refresh is called on another, non-active page which contains a listbox in the same position.
>
>If this is the problem, you can work around it by not calling the refresh of the non-active page.

It doesn't seem to be a case here. We're not calling refresh of other page and other pages don't have listboxes.