Hi, We're on Clearspace 1.3. We've been receiving complaints from users on IE6 that when they try to reply to a discussion thread the text window doesn't open. If they cancel and then click reply again, that usually works.
It's likely it is related to IE 6. We did fix a bunch of IE 6 bugs in 1.4 I believe so you may want to test against that release to see if it solves this issue. If not please reply with as much details as possible as to the IE 6 version, the OS used, etc and we'll see what we can do.