Interesting. Does this occur on all pages (including reviews and articles), or just the forums? And if it's just the forums, is it all the time? I'm thinking it might be some of the ads, but I can't be sure. I know for sure we aren't using any chinese text (directly) on our site. I'll look into it.
Which OS are you using? I just tried Mozilla 1.2.1 on a Windows XP machine, and I reloaded the home page about a dozen times (to see if it was the ads), and I still couldn't reproduce the error. When I get home, I'll try it on Linux.
I'm running Windows 2000 SP3 with Slovenian regional settings, Mozilla 1.2.1 and Sun's Java (J2SE 1.4.1_01 - all languages, including English).
Reloading the page doesn't count. It happens only at the first access. It's not that annoying, but I'm curious why does this occur. I've changed the J2SE version about a week ago, but that shouldn't affect Mozilla since your page doesn't load J2SE...