I have a WordPress client who's currently on Version 2.9.
He is using a theme that is about three years old, very highly customized and altered. It's based on Kubrik. The person who developed it is no longer available, and I find some of the modifications to be almost impenetrable--cannot get my head wrapped around several of them.
It is way, way past time to upgrade this blog to 3.0. Security problems abound, and they're a mess to keep up with. Key plug-ins are also becoming outdated.
My question: How compatible is the old Kubrik with the brand-new WordPress? If I break this theme, I own both halves, and I'd rather minimize the risk.
Any observations, suggestions, words of wisdom, or expressions of "you poor thing" will be enormously appreciated!