This is bunk! I am having the same issue. The only solution is to let the affected page sit for a day or two and then it starts to work again. This only occurs with one page and not the rest. I can edit others just fine.
Does anybody think this has something to do with the number of revisions a page may have? It seems like WordPress is choking on the content and hundreds of revisions to a page.
Has anybody come up with a solution other than letting it sit idle?