Dear twm, may I suggest two things? They might take a bit longer but your replies will be secure. I do it as well because I have lost and it really hurts my nerves if it was a long one.
Type your reply and before you press send, copy the reply. (you might as well use a note pad .doc, but most of the times just right click copy does the trick)
Press send and wait till the first page of messages appear on your screen. This usually is enough evidence that your reply is sent(the subject you posted appears first and must have your name as the latest contributor) , but to be 100% sure click again on it and see your reply.
If it doesn't appear you have it with just two clicks.