iPad iOS upgrade

I have recently upgraded my iPad to iOS 5.0.1 and I am unable to access my contacts. They do not appear as an Icon and they are not there in my settings. Does anyone know why this should be. Any help gratefully received.

I would recommend you do a restore to factory state and re-upgrade to 5.0.1, then restore from your backup.

But before that: have you tried simply powering down the iPad?

Thank you very much for this and I will try it.