Skype always run smoothly on every device. but sometimes, it may generate some problems, like: sign in problem, app opening issues etc. these issues can be related to application. so you need to go ahead and update the application.
sometimes, the problem may be related to server in your area. so you need to make sure, skype server is working fine in your area. you may report for skype problems here and find the result .
If you are having skype not responding problem, i will suggest you to update the account once. i am sure your account will start working fine.