I had the same problem and, after spending hours researching, ran across someone who wrote that wp-table conflicted with their cforms plugin (which I also use.) They disabled cforms, activated wp-table and it worked fine. They then activated cforms and it activated successfully. I did the same thing and was successful. wp-table now works fine. I also read in several places that the only problem with wp-table and 2.5 is the activation process. People who kept it active when they upgraded didn’t see a problem. I haven’t confirmed this however. Hope this helps!
