For some reason, I'm not able to resize the text editing area on my site's WordPress install in Chrome or Firefox. I can resize the HTML editor, which shows a resize indicator in the white text editor area, but the rich editor will not resize even though it shows the resize indicator in the grey area - http://cl.ly/5zgH. I can resize the editor in other WordPress sites I use, but not this one. Has anyone seen this, and do you have any suggestions?
I know this isn't exactly the fix you're looking for, but you could try simply adjusting the default size of the editor in WordPress's settings.
You can go to Settings --> Writing and change the value under "Size of the post box" to make it larger or smaller. I have mine set to 30 lines which is more than enough for a high resolution display.