I would doubt seriously that you NEED a new bow,sounds more like a tuning issue,which you may have on a new bow.

A thread I started a while back may have some pointers on how to get your bow tuned.

http://www.huntingnet.com/forum/tm.aspx?m=2020182


If you WANT a new bow and can AFFORD it,buy it but don't look for excuses to get one.The old ones will do just fine,especially one that is ONLY 5 years old.