@robs:
What is your language setting on IE? It seems you choice the "HTTP Accept Language" in zenPHOTO's language option so the theme display sentences with user's browser settings.
I found that because my Chrome also display your contact form in Chinese, and my default language setting is Chinese, too. (It changed to English after I change my browser's setting.)
BTW, the "random characters" problem may be caused by the PHP's strftime locate, I have the same problem with simplePHPblog and zenPHOTO. All data I found say it only happen on PHP in Windows system, but I have this problem on Linux host, too.