If the problem continues - try having 2 browser windows or tabs open to NT - one for writing the message and the other to use if you get timed out.
you can re log on with the second one with out losing your post.

you may need to clear your browser cache - sometimes that helps too.

[ How to Clear Your Browser's Cache

Every web browser stores web pages, images, and other downloaded content on the computer. This is called the browser's cache. This guide will help you clear your browser's cache.]
http://www.wikihow.com/Clear-Your-Browser%27s-Cache

Or

[How do I clear my web browser's cache?
Each time you access a file through your web browser, the browser caches (stores) it. In this way, the files (including any images on the page) do not have to be retrieved anew from the remote web site each time you click the Back or Forward buttons. You should periodically clear the cache to allow your browser to function more efficiently.

If you do not see instructions for your specific version or browser, search your browser's Help menu for "clear cache".

On this page:

* Windows
o Internet Explorer 7
o Firefox 3

* Mac OS and Mac OS X
o Safari
o Firefox 3]
http://kb.iu.edu/data/ahic.html