On my computer underneath the 'Your Response' box is a blue button which says UPDATE INFORMATION. I'll let Ash know about your prolem.
The team have looked at the missing letters issue raised elsewhere and can't find anything wrong with the system. It may just one of those things or it could be related to an advert that is running. Certainly all the problems seem to occur when Internet Explorer is being used. I use Firefox and have had no problems at all. Others use Google Chrome and they too are not reporting problems.