Advice for sleeping

All of the sudden my son hates his bassinet. The last few nights he has been sleeping for shorter and shorter periods of time. He was sleeping for 2 6-hour stretchs, at night, consistently, for the last few weeks and now he won't sleep for more than an hour in his bassinet. He will sleep for hours in his swing. I broke down and put him there early this morning and he is now getting some much needed sleep. It is one thing for him to snooze in the afternoon in his swing but he can't sleep there at night. Any suggestions? We are talking about getting him a new bassinet in case he just hates that one or a wedge if he needs the angle. Any advice is much appreciated