Hi, Mark - I can't see why you should have a problem like you've explained. Fool around with it and see if you can duplicate it. Just doesn't sound right.
When you check the "preview" box and hit "submit," your message is not really submitted. It produces a test page that shows you what your message will look like when you do submit it. There's an editing box below the display, and that contains the text that will be posted (unless you change it). You should be able to let that sit on your computer for as long as you like. You have to click the "submit" button on that second page before it will post.

If I see URLs in messages, I usually try to turn them into links. I'd rather see an URL than a goofed-up link, however. It's amazing to see what a mess people can make of links. Sometimes, it's impossible to figure out how to fix them.
-Joe Offer-