yep I am getting it on my site as well. At first I thought it was an issue with the language settings of my browser lol.
I'm not getting anything funny, but my mates in UK are. It gave me a bit of a jolt when he messaged me with "Yahoo having a bit of fun with us today mate?" Followed up by a screenshot of one of our sites hat looked like I didn't have the chinese alphabet installed I'm looking forward to international ads though.
Well I saw the same funny charecters today. I did the not take the screenshot though. Again after I refreshed the ads appeared correctly. digiseek