This still happens from time to time, but I have found a work around that seems to work every time I've tried it so far. the work around is this:
Quote the message you want to specifically reply for as usual. Type the reply below the quoted message (i.e. below the text that appears between quote tags, the bits in square brackets).
Select the text between the quote tags (including the tags themselves, the bits in square brackets) and cut that bit out using the cut function in whatever device you're using.
Leave your reply text in the box and post it, and wait for it to post and appear.
Select edit on your new post, and paste in the previously cut text with the quoted post and tags. above your own reply text
Post again and all will be well.
So far this has worked like a charm for me every time, but obviously isn't proof that it's a fix or proper workaround, I may just have got lucky half a dozen times!