Hi Saurabh, we have tested the ToDo app in liferay-portal-6.2-ce-ga2, liferay-portal-6.2-ce-ga3 and liferay-portal-6.2-ee-sp10 and we are able to add multiple tasks without any issues. If you still have problems with it, please provide details here: http://issues.rivetlogic.com/browse/LRA-204.
Thank you for your feedback.
Please use Jira to report bugs and enhancement requests. We have a dedicated Jira project than can be used for this purpose:
Buggy app.... cant add multiple tasks while using in 6.2 CE GA2