this can happen if:

1) corrupt cookie
2) firewall issue blocking cookie
3) your isp is hopping you around ip addresses and causing you to pop over to any of our 4 front end servers. if you hop you will lose session and this can happen

before submitting copy your text just in case so you don't lose it and have to resubmit. lmk if any of the above help you. try deleting your rcu cookie in case corrupt and blow cache out and restart browser

marc