I often copy the view link and manually remove the thread part when posting a link to another comment, which is tedious. Looking at talkread.bml (the first bit of LJ code I ever looked at!), this seems easy to fix: at line 524, remove the text "&thread=$dtid".
I don't have access to anything that will do the diff for me in the right format. Could someone help? Or maybe I should get a goathack - if so, how?