CMS Cannot edit CMS articles including tables
 

Experiencing a very odd error that I hope someone here might be able to assist with.

We're currently in the process of setting up the CMS to replace the news section of our site, and in the process of copying over old articles to this system, we're noticing that we're unable to edit any articles which include tables once they're initially posted. Any other article works fine, but if there's a table in it, created through HTML or through BB code, edits to the article just won't save.

Has anyone else experienced this issue before, or have any idea what's causing it? It can't be a caching issue given that other articles work perfectly, surely...