I am finding the tab UI severely lacking in being intuitive to know which tab is the active tab and what tab the displayed content falls under.
Looking at the attached screen grab, you would find it difficult to know which is the active tab or which tab owns the check box content. I know that my customers are going to find this very confusing as the AJAX tabstrip clearly demarked each tab and didn't remove the focus from the last tab selected or which tab was active for the initial content that was displayed.
It is somewhat difficult to even understand that a tab metaphor is being used because there is no contrast or definition.
Is there any way to adjust the behavior or the styling to make it easier for the end user to easily understand their workspace and not get confused?
Your themes due to lack of contrast make it very difficult to perceive borders you have as the Alpha value is set to such a low value it is registering as almost zero (like 8%) such that older people using the controls may not register the confines (and yes I resemble one of them).