I have travelled in howrah to chennai by howrah chennai mail on 24.05.2011 in sleeper class at S1 coach in tatkal ticket with my family and childrens. I suffered lot of problems which i have ever faced in my reserved rail journey. after the unreserved compartment before S1 coach have bcame filled up number of passengers having second class got in to reserved S1 coach were occuppied the way toilets, sleeping on the floor on the reserved coach and sitting on the doorside which caused hindrance to actually paid customer. No TTE has checked the tickets till next day and ask the unreserved to get away of the coach. No TTE has got into the coach when the train is running in north India. besides the coach was very old and not maintained/cleaned well.