Hey, I thought it was something weird with the setup I had, maybe google chrome and the 256 mb of ram in my work desktop, but I just reproduced this bug here at home on my laptop:
If I type too much into a forum message(reply), it starts slowing down massively and the text appears on the screen in PowerPoint typewriter effect mode :)
It happened at the end of the last paragraph, now i am going slooooooowly.....