Dear Virarajendra
This happens occasionally or sometimes frequently. From my experience, I observed that such thing happens when innumerable submissions happen simultaneously and / or when servers face jam. And further to my observation I found that this happens mostly in the evenings IST, around 5 pm to 9 pm. Sometimes we have to submit again and again. If one or two line messages to be posted you can directly type them. But when you submit a long write-up, it is safe to prepare it in a text programme like MS Word, save it to your system and then copy the text and paste it and submit. This would be the safest way.