Threading broken on nightlies?

[Tim Wunder]

Newsgroup threading doesn't persist after exiting Mail/News on build 
2001051920 and the nightly from May 20'th (don't have the build number, 
I removed it to test an older nightly).

When I read newsgroups, I must click the threading button to view 
threads and it works well enough. But when I leave and come back, 
threading is turned off.

This isn't someone's idea of a "feature", is it?

Regards,
Tim