I would go into "manage applications" and under the "all" tab, go to "internet." There, force stop the browser. Then, clear the cache and data. Now, try restarting the browser and see if you still have the issue. If yes, I'd recommend restarting the phone. This is usually how I've fixed strange behavior from apps.
I noticed the issue with not being able to "submit" anything with the browser as well - but it seemed to clear up on its own. I had probably rebooted the phone for some other reason...
