I have noticed that lately, whenever I try to embed a Youtube video with the [YOUTUBE] tag, it breaks the page table and truncates the post. Any text after the video is lost. Furthermore, if I attempt to edit the post, it will not let me submit the changes, throwing up a dialog box asking me to enter a subject for the post. This happens both inside and outside quote tags.
I was able to replicate this bug most recently on Google Chrome in Windows 7.