I have a similar issue, though I am still using WindowsXP.
Have used ED4.05 for some time with Speechmike 6264, with no problem.
Upgraded Microphone to Speechmike lfh5274, and now find that the buttons don't (ever) start or control the dictation. As you found 'ED recognizes its there and the buttons seem to register correctly on testing the speechmike in ED', but they don't actually do the job. The problem is the same with ED5.33.