Bingo – that solved the problem for me. So nobody’s talked about what’s causing this problem, but it sure looks like old cached information is not compatible with new WordPress 2.8 code.
I’m not 100% sure why reloading portions of the WordPress 2.8 code into your blog’s subdirectories is required, but the clearing of your browser’s cache (including cookies!) is definitely required. I did both steps and now I can see my TinyMCE editing tools.
One small “gotch” that might sneak up on you – I signed out of my blog before reloading the code and clearing my cache. Then when I tried to log in, WordPress acted like my admin account didn’t exist. The solution was to clear my cache again and RELOAD the WordPress sign-in page. Whew!
Good luck to everyone who is still struggling with this one…
– Dr. Jim Anderson
https://www.TheAccidentalSuccessfulCIO.com