I have no problem on my Nexus S with language pack C, but the problem still persists on the Nexus One. I wiped data as well as the caches, and I even tried it using the Mms.apk from the NS 1c build (with a wipe in between), and still no go.
That was the first thing I did (the caches, that is). I am now going to wipe data, too. I was just hoping that I wouldn't have to, since the phone is my mother's daily driver.
Unfortunately the bug still persists on the Nexus One. I can pull up the conversation list fine, but when I select a conversation I get a FC. I pulled a logcat, and have pasted it below: