Actually this is a xfree86 bug, not a gentoo bug; and there's a patch available on their site. Could someone please update the xfree ebuild to incoporate these patches. I have exactly the same problem as described in the above link, and I'm afraid it affects other CJK users as well; as a sidenote, I have not been able to use Chinese since I upgraded from 4.1.0 to 4.2.0; after a couple of days' searching, I found it's a bug with xfree, and they already have a solution! Best Regards, Joseph H. Yao
Fixed in xfree-4.2.0-r6.